mirror of https://git.ffmpeg.org/ffmpeg.git
1549 lines
47 KiB
C
1549 lines
47 KiB
C
/*
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* MPEG1/2 mux/demux
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* Copyright (c) 2000, 2001, 2002 Fabrice Bellard.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include "avformat.h"
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#define MAX_PAYLOAD_SIZE 4096
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//#define DEBUG_SEEK
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#undef NDEBUG
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#include <assert.h>
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typedef struct {
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uint8_t buffer[MAX_PAYLOAD_SIZE];
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int buffer_ptr;
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int nb_frames; /* number of starting frame encountered (AC3) */
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int frame_start_offset; /* starting offset of the frame + 1 (0 if none) */
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uint8_t id;
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int max_buffer_size; /* in bytes */
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int packet_number;
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int64_t start_pts;
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int64_t start_dts;
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uint8_t lpcm_header[3];
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int lpcm_align;
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} StreamInfo;
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typedef struct {
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int packet_size; /* required packet size */
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int packet_number;
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int pack_header_freq; /* frequency (in packets^-1) at which we send pack headers */
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int system_header_freq;
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int system_header_size;
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int mux_rate; /* bitrate in units of 50 bytes/s */
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/* stream info */
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int audio_bound;
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int video_bound;
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int is_mpeg2;
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int is_vcd;
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int is_svcd;
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int scr_stream_index; /* stream from which the system clock is
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computed (VBR case) */
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int64_t last_scr; /* current system clock */
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double vcd_padding_bitrate;
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int64_t vcd_padding_bytes_written;
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} MpegMuxContext;
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#define PACK_START_CODE ((unsigned int)0x000001ba)
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#define SYSTEM_HEADER_START_CODE ((unsigned int)0x000001bb)
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#define SEQUENCE_END_CODE ((unsigned int)0x000001b7)
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#define PACKET_START_CODE_MASK ((unsigned int)0xffffff00)
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#define PACKET_START_CODE_PREFIX ((unsigned int)0x00000100)
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#define ISO_11172_END_CODE ((unsigned int)0x000001b9)
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/* mpeg2 */
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#define PROGRAM_STREAM_MAP 0x1bc
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#define PRIVATE_STREAM_1 0x1bd
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#define PADDING_STREAM 0x1be
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#define PRIVATE_STREAM_2 0x1bf
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#define AUDIO_ID 0xc0
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#define VIDEO_ID 0xe0
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#define AC3_ID 0x80
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#define LPCM_ID 0xa0
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static const int lpcm_freq_tab[4] = { 48000, 96000, 44100, 32000 };
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#ifdef CONFIG_ENCODERS
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extern AVOutputFormat mpeg1system_mux;
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extern AVOutputFormat mpeg1vcd_mux;
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extern AVOutputFormat mpeg2vob_mux;
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extern AVOutputFormat mpeg2svcd_mux;
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static int put_pack_header(AVFormatContext *ctx,
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uint8_t *buf, int64_t timestamp)
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{
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MpegMuxContext *s = ctx->priv_data;
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PutBitContext pb;
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init_put_bits(&pb, buf, 128);
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put_bits(&pb, 32, PACK_START_CODE);
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if (s->is_mpeg2) {
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put_bits(&pb, 2, 0x1);
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} else {
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put_bits(&pb, 4, 0x2);
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}
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put_bits(&pb, 3, (uint32_t)((timestamp >> 30) & 0x07));
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put_bits(&pb, 1, 1);
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put_bits(&pb, 15, (uint32_t)((timestamp >> 15) & 0x7fff));
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put_bits(&pb, 1, 1);
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put_bits(&pb, 15, (uint32_t)((timestamp) & 0x7fff));
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put_bits(&pb, 1, 1);
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if (s->is_mpeg2) {
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/* clock extension */
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put_bits(&pb, 9, 0);
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}
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put_bits(&pb, 1, 1);
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put_bits(&pb, 22, s->mux_rate);
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put_bits(&pb, 1, 1);
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if (s->is_mpeg2) {
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put_bits(&pb, 1, 1);
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put_bits(&pb, 5, 0x1f); /* reserved */
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put_bits(&pb, 3, 0); /* stuffing length */
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}
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flush_put_bits(&pb);
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return pbBufPtr(&pb) - pb.buf;
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}
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static int put_system_header(AVFormatContext *ctx, uint8_t *buf,int only_for_stream_id)
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{
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MpegMuxContext *s = ctx->priv_data;
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int size, rate_bound, i, private_stream_coded, id;
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PutBitContext pb;
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init_put_bits(&pb, buf, 128);
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put_bits(&pb, 32, SYSTEM_HEADER_START_CODE);
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put_bits(&pb, 16, 0);
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put_bits(&pb, 1, 1);
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rate_bound = s->mux_rate; /* maximum bit rate of the multiplexed stream */
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put_bits(&pb, 22, rate_bound);
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put_bits(&pb, 1, 1); /* marker */
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if (s->is_vcd && only_for_stream_id==VIDEO_ID) {
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/* This header applies only to the video stream (see VCD standard p. IV-7)*/
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put_bits(&pb, 6, 0);
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} else
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put_bits(&pb, 6, s->audio_bound);
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if (s->is_vcd)
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put_bits(&pb, 1, 0); /* see VCD standard, p. IV-7*/
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else
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put_bits(&pb, 1, 1); /* variable bitrate*/
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put_bits(&pb, 1, 1); /* non constrainted bit stream */
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if (s->is_vcd) {
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/* see VCD standard p IV-7 */
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put_bits(&pb, 1, 1); /* audio locked */
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put_bits(&pb, 1, 1); /* video locked */
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} else {
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put_bits(&pb, 1, 0); /* audio locked */
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put_bits(&pb, 1, 0); /* video locked */
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}
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put_bits(&pb, 1, 1); /* marker */
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if (s->is_vcd && only_for_stream_id==AUDIO_ID) {
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/* This header applies only to the audio stream (see VCD standard p. IV-7)*/
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put_bits(&pb, 5, 0);
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} else
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put_bits(&pb, 5, s->video_bound);
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put_bits(&pb, 8, 0xff); /* reserved byte */
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/* audio stream info */
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private_stream_coded = 0;
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for(i=0;i<ctx->nb_streams;i++) {
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StreamInfo *stream = ctx->streams[i]->priv_data;
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/* For VCDs, only include the stream info for the stream
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that the pack which contains this system belongs to.
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(see VCD standard p. IV-7) */
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if ( !s->is_vcd || stream->id==only_for_stream_id
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|| only_for_stream_id==0) {
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id = stream->id;
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if (id < 0xc0) {
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/* special case for private streams (AC3 use that) */
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if (private_stream_coded)
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continue;
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private_stream_coded = 1;
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id = 0xbd;
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}
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put_bits(&pb, 8, id); /* stream ID */
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put_bits(&pb, 2, 3);
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if (id < 0xe0) {
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/* audio */
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put_bits(&pb, 1, 0);
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put_bits(&pb, 13, stream->max_buffer_size / 128);
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} else {
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/* video */
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put_bits(&pb, 1, 1);
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put_bits(&pb, 13, stream->max_buffer_size / 1024);
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}
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}
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}
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flush_put_bits(&pb);
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size = pbBufPtr(&pb) - pb.buf;
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/* patch packet size */
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buf[4] = (size - 6) >> 8;
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buf[5] = (size - 6) & 0xff;
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return size;
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}
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static int get_system_header_size(AVFormatContext *ctx)
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{
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int buf_index, i, private_stream_coded;
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StreamInfo *stream;
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buf_index = 12;
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private_stream_coded = 0;
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for(i=0;i<ctx->nb_streams;i++) {
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stream = ctx->streams[i]->priv_data;
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if (stream->id < 0xc0) {
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if (private_stream_coded)
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continue;
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private_stream_coded = 1;
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}
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buf_index += 3;
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}
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return buf_index;
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}
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static int mpeg_mux_init(AVFormatContext *ctx)
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{
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MpegMuxContext *s = ctx->priv_data;
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int bitrate, i, mpa_id, mpv_id, ac3_id, lpcm_id, j;
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AVStream *st;
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StreamInfo *stream;
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int audio_bitrate;
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int video_bitrate;
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s->packet_number = 0;
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s->is_vcd = (ctx->oformat == &mpeg1vcd_mux);
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s->is_svcd = (ctx->oformat == &mpeg2svcd_mux);
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s->is_mpeg2 = (ctx->oformat == &mpeg2vob_mux || ctx->oformat == &mpeg2svcd_mux);
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if (s->is_vcd || s->is_svcd)
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s->packet_size = 2324; /* VCD/SVCD packet size */
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else
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s->packet_size = 2048;
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s->vcd_padding_bytes_written = 0;
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s->vcd_padding_bitrate=0;
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s->audio_bound = 0;
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s->video_bound = 0;
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mpa_id = AUDIO_ID;
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ac3_id = AC3_ID;
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mpv_id = VIDEO_ID;
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lpcm_id = LPCM_ID;
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s->scr_stream_index = -1;
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for(i=0;i<ctx->nb_streams;i++) {
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st = ctx->streams[i];
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stream = av_mallocz(sizeof(StreamInfo));
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if (!stream)
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goto fail;
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st->priv_data = stream;
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switch(st->codec.codec_type) {
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case CODEC_TYPE_AUDIO:
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if (st->codec.codec_id == CODEC_ID_AC3) {
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stream->id = ac3_id++;
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} else if (st->codec.codec_id == CODEC_ID_PCM_S16BE) {
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stream->id = lpcm_id++;
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for(j = 0; j < 4; j++) {
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if (lpcm_freq_tab[j] == st->codec.sample_rate)
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break;
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}
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if (j == 4)
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goto fail;
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if (st->codec.channels > 8)
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return -1;
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stream->lpcm_header[0] = 0x0c;
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stream->lpcm_header[1] = (st->codec.channels - 1) | (j << 4);
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stream->lpcm_header[2] = 0x80;
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stream->lpcm_align = st->codec.channels * 2;
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} else {
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stream->id = mpa_id++;
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}
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stream->max_buffer_size = 4 * 1024;
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s->audio_bound++;
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break;
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case CODEC_TYPE_VIDEO:
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/* by default, video is used for the SCR computation */
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if (s->scr_stream_index == -1)
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s->scr_stream_index = i;
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stream->id = mpv_id++;
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stream->max_buffer_size = 46 * 1024;
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s->video_bound++;
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break;
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default:
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av_abort();
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}
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}
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/* if no SCR, use first stream (audio) */
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if (s->scr_stream_index == -1)
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s->scr_stream_index = 0;
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bitrate = 0;
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audio_bitrate = 0;
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video_bitrate = 0;
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for(i=0;i<ctx->nb_streams;i++) {
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st = ctx->streams[i];
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stream = (StreamInfo*) st->priv_data;
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bitrate += st->codec.bit_rate;
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if (stream->id==AUDIO_ID)
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audio_bitrate += st->codec.bit_rate;
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else if (stream->id==VIDEO_ID)
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video_bitrate += st->codec.bit_rate;
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}
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if (s->is_vcd) {
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double overhead_rate;
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/* The VCD standard mandates that the mux_rate field is 3528
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(see standard p. IV-6).
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The value is actually "wrong", i.e. if you calculate
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it using the normal formula and the 75 sectors per second transfer
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rate you get a different value because the real pack size is 2324,
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not 2352. But the standard explicitly specifies that the mux_rate
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field in the header must have this value.*/
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s->mux_rate=2352 * 75 / 50; /* = 3528*/
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/* The VCD standard states that the muxed stream must be
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exactly 75 packs / second (the data rate of a single speed cdrom).
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Since the video bitrate (probably 1150000 bits/sec) will be below
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the theoretical maximum we have to add some padding packets
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to make up for the lower data rate.
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(cf. VCD standard p. IV-6 )*/
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/* Add the header overhead to the data rate.
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2279 data bytes per audio pack, 2294 data bytes per video pack*/
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overhead_rate = ((audio_bitrate / 8.0) / 2279) * (2324 - 2279);
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overhead_rate += ((video_bitrate / 8.0) / 2294) * (2324 - 2294);
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overhead_rate *= 8;
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/* Add padding so that the full bitrate is 2324*75 bytes/sec */
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s->vcd_padding_bitrate = 2324 * 75 * 8 - (bitrate + overhead_rate);
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} else {
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/* we increase slightly the bitrate to take into account the
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headers. XXX: compute it exactly */
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bitrate += 2000;
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s->mux_rate = (bitrate + (8 * 50) - 1) / (8 * 50);
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}
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if (s->is_vcd || s->is_mpeg2)
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/* every packet */
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s->pack_header_freq = 1;
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else
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/* every 2 seconds */
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s->pack_header_freq = 2 * bitrate / s->packet_size / 8;
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/* the above seems to make pack_header_freq zero sometimes */
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if (s->pack_header_freq == 0)
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s->pack_header_freq = 1;
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if (s->is_mpeg2)
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/* every 200 packets. Need to look at the spec. */
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s->system_header_freq = s->pack_header_freq * 40;
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else if (s->is_vcd)
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/* the standard mandates that there are only two system headers
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in the whole file: one in the first packet of each stream.
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(see standard p. IV-7 and IV-8) */
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s->system_header_freq = 0x7fffffff;
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else
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s->system_header_freq = s->pack_header_freq * 5;
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for(i=0;i<ctx->nb_streams;i++) {
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stream = ctx->streams[i]->priv_data;
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stream->buffer_ptr = 0;
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stream->packet_number = 0;
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stream->start_pts = AV_NOPTS_VALUE;
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stream->start_dts = AV_NOPTS_VALUE;
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}
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s->system_header_size = get_system_header_size(ctx);
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s->last_scr = 0;
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return 0;
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fail:
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for(i=0;i<ctx->nb_streams;i++) {
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av_free(ctx->streams[i]->priv_data);
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}
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return -ENOMEM;
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}
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static inline void put_timestamp(ByteIOContext *pb, int id, int64_t timestamp)
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{
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put_byte(pb,
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(id << 4) |
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(((timestamp >> 30) & 0x07) << 1) |
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1);
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put_be16(pb, (uint16_t)((((timestamp >> 15) & 0x7fff) << 1) | 1));
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put_be16(pb, (uint16_t)((((timestamp) & 0x7fff) << 1) | 1));
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}
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|
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/* return the number of padding bytes that should be inserted into
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the multiplexed stream.*/
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static int get_vcd_padding_size(AVFormatContext *ctx, int64_t pts)
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{
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MpegMuxContext *s = ctx->priv_data;
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int pad_bytes = 0;
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if (s->vcd_padding_bitrate > 0 && pts!=AV_NOPTS_VALUE)
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{
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int64_t full_pad_bytes;
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full_pad_bytes = (int64_t)((s->vcd_padding_bitrate * (pts / 90000.0)) / 8.0);
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pad_bytes = (int) (full_pad_bytes - s->vcd_padding_bytes_written);
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if (pad_bytes<0)
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/* might happen if we have already padded to a later timestamp. This
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can occur if another stream has already advanced further.*/
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pad_bytes=0;
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}
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return pad_bytes;
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}
|
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|
|
|
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/* return the exact available payload size for the next packet for
|
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stream 'stream_index'. 'pts' and 'dts' are only used to know if
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timestamps are needed in the packet header. */
|
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static int get_packet_payload_size(AVFormatContext *ctx, int stream_index,
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int64_t pts, int64_t dts)
|
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{
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MpegMuxContext *s = ctx->priv_data;
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int buf_index;
|
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StreamInfo *stream;
|
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|
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stream = ctx->streams[stream_index]->priv_data;
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buf_index = 0;
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if (((s->packet_number % s->pack_header_freq) == 0)) {
|
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/* pack header size */
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if (s->is_mpeg2)
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buf_index += 14;
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else
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buf_index += 12;
|
|
|
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if (s->is_vcd) {
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/* there is exactly one system header for each stream in a VCD MPEG,
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One in the very first video packet and one in the very first
|
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audio packet (see VCD standard p. IV-7 and IV-8).*/
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|
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if (stream->packet_number==0)
|
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/* The system headers refer only to the stream they occur in,
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so they have a constant size.*/
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buf_index += 15;
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|
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} else {
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if ((s->packet_number % s->system_header_freq) == 0)
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buf_index += s->system_header_size;
|
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}
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}
|
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|
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if (s->is_vcd && stream->packet_number==0)
|
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/* the first pack of each stream contains only the pack header,
|
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the system header and some padding (see VCD standard p. IV-6)
|
|
Add the padding size, so that the actual payload becomes 0.*/
|
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buf_index += s->packet_size - buf_index;
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else {
|
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/* packet header size */
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buf_index += 6;
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if (s->is_mpeg2)
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buf_index += 3;
|
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if (pts != AV_NOPTS_VALUE) {
|
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if (dts != pts)
|
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buf_index += 5 + 5;
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else
|
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buf_index += 5;
|
|
|
|
} else {
|
|
if (!s->is_mpeg2)
|
|
buf_index++;
|
|
}
|
|
|
|
if (stream->id < 0xc0) {
|
|
/* AC3/LPCM private data header */
|
|
buf_index += 4;
|
|
if (stream->id >= 0xa0) {
|
|
int n;
|
|
buf_index += 3;
|
|
/* NOTE: we round the payload size to an integer number of
|
|
LPCM samples */
|
|
n = (s->packet_size - buf_index) % stream->lpcm_align;
|
|
if (n)
|
|
buf_index += (stream->lpcm_align - n);
|
|
}
|
|
}
|
|
|
|
if (s->is_vcd && stream->id == AUDIO_ID)
|
|
/* The VCD standard demands that 20 zero bytes follow
|
|
each audio packet (see standard p. IV-8).*/
|
|
buf_index+=20;
|
|
}
|
|
return s->packet_size - buf_index;
|
|
}
|
|
|
|
/* Write an MPEG padding packet header. */
|
|
static int put_padding_header(AVFormatContext *ctx,uint8_t* buf, int full_padding_size)
|
|
{
|
|
MpegMuxContext *s = ctx->priv_data;
|
|
int size = full_padding_size - 6; /* subtract header length */
|
|
|
|
buf[0] = (uint8_t)(PADDING_STREAM >> 24);
|
|
buf[1] = (uint8_t)(PADDING_STREAM >> 16);
|
|
buf[2] = (uint8_t)(PADDING_STREAM >> 8);
|
|
buf[3] = (uint8_t)(PADDING_STREAM);
|
|
buf[4] = (uint8_t)(size >> 8);
|
|
buf[5] = (uint8_t)(size & 0xff);
|
|
|
|
if (!s->is_mpeg2) {
|
|
buf[6] = 0x0f;
|
|
return 7;
|
|
} else
|
|
return 6;
|
|
}
|
|
|
|
static void put_padding_packet(AVFormatContext *ctx, ByteIOContext *pb,int packet_bytes)
|
|
{
|
|
uint8_t buffer[7];
|
|
int size, i;
|
|
|
|
size = put_padding_header(ctx,buffer, packet_bytes);
|
|
put_buffer(pb, buffer, size);
|
|
packet_bytes -= size;
|
|
|
|
for(i=0;i<packet_bytes;i++)
|
|
put_byte(pb, 0xff);
|
|
}
|
|
|
|
|
|
/* flush the packet on stream stream_index */
|
|
static void flush_packet(AVFormatContext *ctx, int stream_index,
|
|
int64_t pts, int64_t dts, int64_t scr)
|
|
{
|
|
MpegMuxContext *s = ctx->priv_data;
|
|
StreamInfo *stream = ctx->streams[stream_index]->priv_data;
|
|
uint8_t *buf_ptr;
|
|
int size, payload_size, startcode, id, stuffing_size, i, header_len;
|
|
int packet_size;
|
|
uint8_t buffer[128];
|
|
int zero_trail_bytes = 0;
|
|
int pad_packet_bytes = 0;
|
|
|
|
id = stream->id;
|
|
|
|
#if 0
|
|
printf("packet ID=%2x PTS=%0.3f\n",
|
|
id, pts / 90000.0);
|
|
#endif
|
|
|
|
buf_ptr = buffer;
|
|
|
|
if (((s->packet_number % s->pack_header_freq) == 0)) {
|
|
/* output pack and systems header if needed */
|
|
size = put_pack_header(ctx, buf_ptr, scr);
|
|
buf_ptr += size;
|
|
|
|
if (s->is_vcd) {
|
|
/* there is exactly one system header for each stream in a VCD MPEG,
|
|
One in the very first video packet and one in the very first
|
|
audio packet (see VCD standard p. IV-7 and IV-8).*/
|
|
|
|
if (stream->packet_number==0) {
|
|
size = put_system_header(ctx, buf_ptr, id);
|
|
buf_ptr += size;
|
|
}
|
|
} else {
|
|
if ((s->packet_number % s->system_header_freq) == 0) {
|
|
size = put_system_header(ctx, buf_ptr, 0);
|
|
buf_ptr += size;
|
|
}
|
|
}
|
|
}
|
|
size = buf_ptr - buffer;
|
|
put_buffer(&ctx->pb, buffer, size);
|
|
|
|
packet_size = s->packet_size - size;
|
|
|
|
if (s->is_vcd && id == AUDIO_ID)
|
|
/* The VCD standard demands that 20 zero bytes follow
|
|
each audio pack (see standard p. IV-8).*/
|
|
zero_trail_bytes += 20;
|
|
|
|
if (s->is_vcd && stream->packet_number==0) {
|
|
/* the first pack of each stream contains only the pack header,
|
|
the system header and lots of padding (see VCD standard p. IV-6).
|
|
In the case of an audio pack, 20 zero bytes are also added at
|
|
the end.*/
|
|
pad_packet_bytes = packet_size - zero_trail_bytes;
|
|
}
|
|
|
|
packet_size -= pad_packet_bytes + zero_trail_bytes;
|
|
|
|
if (packet_size > 0) {
|
|
|
|
/* packet header size */
|
|
packet_size -= 6;
|
|
|
|
/* packet header */
|
|
if (s->is_mpeg2) {
|
|
header_len = 3;
|
|
} else {
|
|
header_len = 0;
|
|
}
|
|
if (pts != AV_NOPTS_VALUE) {
|
|
if (dts != pts)
|
|
header_len += 5 + 5;
|
|
else
|
|
header_len += 5;
|
|
} else {
|
|
if (!s->is_mpeg2)
|
|
header_len++;
|
|
}
|
|
|
|
payload_size = packet_size - header_len;
|
|
if (id < 0xc0) {
|
|
startcode = PRIVATE_STREAM_1;
|
|
payload_size -= 4;
|
|
if (id >= 0xa0)
|
|
payload_size -= 3;
|
|
} else {
|
|
startcode = 0x100 + id;
|
|
}
|
|
|
|
stuffing_size = payload_size - stream->buffer_ptr;
|
|
if (stuffing_size < 0)
|
|
stuffing_size = 0;
|
|
put_be32(&ctx->pb, startcode);
|
|
|
|
put_be16(&ctx->pb, packet_size);
|
|
|
|
if (!s->is_mpeg2)
|
|
for(i=0;i<stuffing_size;i++)
|
|
put_byte(&ctx->pb, 0xff);
|
|
|
|
if (s->is_mpeg2) {
|
|
put_byte(&ctx->pb, 0x80); /* mpeg2 id */
|
|
|
|
if (pts != AV_NOPTS_VALUE) {
|
|
if (dts != pts) {
|
|
put_byte(&ctx->pb, 0xc0); /* flags */
|
|
put_byte(&ctx->pb, header_len - 3 + stuffing_size);
|
|
put_timestamp(&ctx->pb, 0x03, pts);
|
|
put_timestamp(&ctx->pb, 0x01, dts);
|
|
} else {
|
|
put_byte(&ctx->pb, 0x80); /* flags */
|
|
put_byte(&ctx->pb, header_len - 3 + stuffing_size);
|
|
put_timestamp(&ctx->pb, 0x02, pts);
|
|
}
|
|
} else {
|
|
put_byte(&ctx->pb, 0x00); /* flags */
|
|
put_byte(&ctx->pb, header_len - 3 + stuffing_size);
|
|
}
|
|
} else {
|
|
if (pts != AV_NOPTS_VALUE) {
|
|
if (dts != pts) {
|
|
put_timestamp(&ctx->pb, 0x03, pts);
|
|
put_timestamp(&ctx->pb, 0x01, dts);
|
|
} else {
|
|
put_timestamp(&ctx->pb, 0x02, pts);
|
|
}
|
|
} else {
|
|
put_byte(&ctx->pb, 0x0f);
|
|
}
|
|
}
|
|
|
|
if (startcode == PRIVATE_STREAM_1) {
|
|
put_byte(&ctx->pb, id);
|
|
if (id >= 0xa0) {
|
|
/* LPCM (XXX: check nb_frames) */
|
|
put_byte(&ctx->pb, 7);
|
|
put_be16(&ctx->pb, 4); /* skip 3 header bytes */
|
|
put_byte(&ctx->pb, stream->lpcm_header[0]);
|
|
put_byte(&ctx->pb, stream->lpcm_header[1]);
|
|
put_byte(&ctx->pb, stream->lpcm_header[2]);
|
|
} else {
|
|
/* AC3 */
|
|
put_byte(&ctx->pb, stream->nb_frames);
|
|
put_be16(&ctx->pb, stream->frame_start_offset);
|
|
}
|
|
}
|
|
|
|
if (s->is_mpeg2)
|
|
for(i=0;i<stuffing_size;i++)
|
|
put_byte(&ctx->pb, 0xff);
|
|
|
|
/* output data */
|
|
put_buffer(&ctx->pb, stream->buffer, payload_size - stuffing_size);
|
|
}
|
|
|
|
if (pad_packet_bytes > 0)
|
|
put_padding_packet(ctx,&ctx->pb, pad_packet_bytes);
|
|
|
|
for(i=0;i<zero_trail_bytes;i++)
|
|
put_byte(&ctx->pb, 0x00);
|
|
|
|
put_flush_packet(&ctx->pb);
|
|
|
|
s->packet_number++;
|
|
stream->packet_number++;
|
|
stream->nb_frames = 0;
|
|
stream->frame_start_offset = 0;
|
|
}
|
|
|
|
static void put_vcd_padding_sector(AVFormatContext *ctx)
|
|
{
|
|
/* There are two ways to do this padding: writing a sector/pack
|
|
of 0 values, or writing an MPEG padding pack. Both seem to
|
|
work with most decoders, BUT the VCD standard only allows a 0-sector
|
|
(see standard p. IV-4, IV-5).
|
|
So a 0-sector it is...*/
|
|
|
|
MpegMuxContext *s = ctx->priv_data;
|
|
int i;
|
|
|
|
for(i=0;i<s->packet_size;i++)
|
|
put_byte(&ctx->pb, 0);
|
|
|
|
s->vcd_padding_bytes_written += s->packet_size;
|
|
|
|
put_flush_packet(&ctx->pb);
|
|
|
|
/* increasing the packet number is correct. The SCR of the following packs
|
|
is calculated from the packet_number and it has to include the padding
|
|
sector (it represents the sector index, not the MPEG pack index)
|
|
(see VCD standard p. IV-6)*/
|
|
s->packet_number++;
|
|
}
|
|
|
|
/* XXX: move that to upper layer */
|
|
/* XXX: we assume that there are always 'max_b_frames' between
|
|
reference frames. A better solution would be to use the AVFrame pts
|
|
field */
|
|
static void compute_pts_dts(AVStream *st, int64_t *ppts, int64_t *pdts,
|
|
int64_t timestamp)
|
|
{
|
|
int frame_delay;
|
|
int64_t pts, dts;
|
|
|
|
if (st->codec.codec_type == CODEC_TYPE_VIDEO &&
|
|
st->codec.max_b_frames != 0) {
|
|
frame_delay = (st->codec.frame_rate_base * 90000LL) /
|
|
st->codec.frame_rate;
|
|
if (timestamp == 0) {
|
|
/* specific case for first frame : DTS just before */
|
|
pts = timestamp;
|
|
dts = timestamp - frame_delay;
|
|
} else {
|
|
timestamp -= frame_delay;
|
|
if (st->codec.coded_frame->pict_type == FF_B_TYPE) {
|
|
/* B frames has identical pts/dts */
|
|
pts = timestamp;
|
|
dts = timestamp;
|
|
} else {
|
|
/* a reference frame has a pts equal to the dts of the
|
|
_next_ one */
|
|
dts = timestamp;
|
|
pts = timestamp + (st->codec.max_b_frames + 1) * frame_delay;
|
|
}
|
|
}
|
|
#if 1
|
|
printf("pts=%0.3f dts=%0.3f pict_type=%c\n",
|
|
pts / 90000.0, dts / 90000.0,
|
|
av_get_pict_type_char(st->codec.coded_frame->pict_type));
|
|
#endif
|
|
} else {
|
|
pts = timestamp;
|
|
dts = timestamp;
|
|
}
|
|
*ppts = pts & ((1LL << 33) - 1);
|
|
*pdts = dts & ((1LL << 33) - 1);
|
|
}
|
|
|
|
static int64_t update_scr(AVFormatContext *ctx,int stream_index,int64_t pts)
|
|
{
|
|
MpegMuxContext *s = ctx->priv_data;
|
|
int64_t scr;
|
|
|
|
if (s->is_vcd)
|
|
/* Since the data delivery rate is constant, SCR is computed
|
|
using the formula C + i * 1200 where C is the start constant
|
|
and i is the pack index.
|
|
It is recommended that SCR 0 is at the beginning of the VCD front
|
|
margin (a sequence of empty Form 2 sectors on the CD).
|
|
It is recommended that the front margin is 30 sectors long, so
|
|
we use C = 30*1200 = 36000
|
|
(Note that even if the front margin is not 30 sectors the file
|
|
will still be correct according to the standard. It just won't have
|
|
the "recommended" value).*/
|
|
scr = 36000 + s->packet_number * 1200;
|
|
else {
|
|
/* XXX I believe this calculation of SCR is wrong. SCR
|
|
specifies at which time the data should enter the decoder.
|
|
Two packs cannot enter the decoder at the same time. */
|
|
|
|
/* XXX: system clock should be computed precisely, especially for
|
|
CBR case. The current mode gives at least something coherent */
|
|
if (stream_index == s->scr_stream_index
|
|
&& pts != AV_NOPTS_VALUE)
|
|
scr = pts;
|
|
else
|
|
scr = s->last_scr;
|
|
}
|
|
|
|
s->last_scr=scr;
|
|
|
|
return scr;
|
|
}
|
|
|
|
|
|
static int mpeg_mux_write_packet(AVFormatContext *ctx, int stream_index,
|
|
const uint8_t *buf, int size,
|
|
int64_t timestamp)
|
|
{
|
|
MpegMuxContext *s = ctx->priv_data;
|
|
AVStream *st = ctx->streams[stream_index];
|
|
StreamInfo *stream = st->priv_data;
|
|
int64_t pts, dts, new_start_pts, new_start_dts;
|
|
int len, avail_size;
|
|
|
|
compute_pts_dts(st, &pts, &dts, timestamp);
|
|
|
|
|
|
#if 0
|
|
update_scr(ctx,stream_index,pts);
|
|
|
|
printf("%d: pts=%0.3f dts=%0.3f scr=%0.3f\n",
|
|
stream_index,
|
|
pts / 90000.0,
|
|
dts / 90000.0,
|
|
s->last_scr / 90000.0);
|
|
#endif
|
|
|
|
/* we assume here that pts != AV_NOPTS_VALUE */
|
|
new_start_pts = stream->start_pts;
|
|
new_start_dts = stream->start_dts;
|
|
|
|
if (stream->start_pts == AV_NOPTS_VALUE) {
|
|
new_start_pts = pts;
|
|
new_start_dts = dts;
|
|
}
|
|
avail_size = get_packet_payload_size(ctx, stream_index,
|
|
new_start_pts,
|
|
new_start_dts);
|
|
if (stream->buffer_ptr >= avail_size) {
|
|
|
|
update_scr(ctx,stream_index,stream->start_pts);
|
|
|
|
/* unlikely case: outputing the pts or dts increase the packet
|
|
size so that we cannot write the start of the next
|
|
packet. In this case, we must flush the current packet with
|
|
padding.
|
|
Note: this always happens for the first audio and video packet
|
|
in a VCD file, since they do not carry any data.*/
|
|
flush_packet(ctx, stream_index,
|
|
stream->start_pts, stream->start_dts, s->last_scr);
|
|
stream->buffer_ptr = 0;
|
|
}
|
|
stream->start_pts = new_start_pts;
|
|
stream->start_dts = new_start_dts;
|
|
stream->nb_frames++;
|
|
if (stream->frame_start_offset == 0)
|
|
stream->frame_start_offset = stream->buffer_ptr;
|
|
while (size > 0) {
|
|
avail_size = get_packet_payload_size(ctx, stream_index,
|
|
stream->start_pts,
|
|
stream->start_dts);
|
|
len = avail_size - stream->buffer_ptr;
|
|
if (len > size)
|
|
len = size;
|
|
memcpy(stream->buffer + stream->buffer_ptr, buf, len);
|
|
stream->buffer_ptr += len;
|
|
buf += len;
|
|
size -= len;
|
|
if (stream->buffer_ptr >= avail_size) {
|
|
|
|
update_scr(ctx,stream_index,stream->start_pts);
|
|
|
|
/* if packet full, we send it now */
|
|
flush_packet(ctx, stream_index,
|
|
stream->start_pts, stream->start_dts, s->last_scr);
|
|
stream->buffer_ptr = 0;
|
|
|
|
if (s->is_vcd) {
|
|
/* Write one or more padding sectors, if necessary, to reach
|
|
the constant overall bitrate.*/
|
|
int vcd_pad_bytes;
|
|
|
|
while((vcd_pad_bytes = get_vcd_padding_size(ctx,stream->start_pts) ) >= s->packet_size)
|
|
put_vcd_padding_sector(ctx);
|
|
}
|
|
|
|
/* Make sure only the FIRST pes packet for this frame has
|
|
a timestamp */
|
|
stream->start_pts = AV_NOPTS_VALUE;
|
|
stream->start_dts = AV_NOPTS_VALUE;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mpeg_mux_end(AVFormatContext *ctx)
|
|
{
|
|
MpegMuxContext *s = ctx->priv_data;
|
|
StreamInfo *stream;
|
|
int i;
|
|
|
|
/* flush each packet */
|
|
for(i=0;i<ctx->nb_streams;i++) {
|
|
stream = ctx->streams[i]->priv_data;
|
|
if (stream->buffer_ptr > 0) {
|
|
update_scr(ctx,i,stream->start_pts);
|
|
|
|
/* NOTE: we can always write the remaining data as it was
|
|
tested before in mpeg_mux_write_packet() */
|
|
flush_packet(ctx, i, stream->start_pts, stream->start_dts,
|
|
s->last_scr);
|
|
}
|
|
}
|
|
|
|
/* End header according to MPEG1 systems standard. We do not write
|
|
it as it is usually not needed by decoders and because it
|
|
complicates MPEG stream concatenation. */
|
|
//put_be32(&ctx->pb, ISO_11172_END_CODE);
|
|
//put_flush_packet(&ctx->pb);
|
|
|
|
for(i=0;i<ctx->nb_streams;i++)
|
|
av_freep(&ctx->streams[i]->priv_data);
|
|
|
|
return 0;
|
|
}
|
|
#endif //CONFIG_ENCODERS
|
|
|
|
/*********************************************/
|
|
/* demux code */
|
|
|
|
#define MAX_SYNC_SIZE 100000
|
|
|
|
static int mpegps_probe(AVProbeData *p)
|
|
{
|
|
int code, c, i;
|
|
|
|
code = 0xff;
|
|
/* we search the first start code. If it is a packet start code,
|
|
then we decide it is mpeg ps. We do not send highest value to
|
|
give a chance to mpegts */
|
|
/* NOTE: the search range was restricted to avoid too many false
|
|
detections */
|
|
|
|
if (p->buf_size < 6)
|
|
return 0;
|
|
|
|
for (i = 0; i < 20; i++) {
|
|
c = p->buf[i];
|
|
code = (code << 8) | c;
|
|
if ((code & 0xffffff00) == 0x100) {
|
|
if (code == PACK_START_CODE ||
|
|
code == SYSTEM_HEADER_START_CODE ||
|
|
(code >= 0x1e0 && code <= 0x1ef) ||
|
|
(code >= 0x1c0 && code <= 0x1df) ||
|
|
code == PRIVATE_STREAM_2 ||
|
|
code == PROGRAM_STREAM_MAP ||
|
|
code == PRIVATE_STREAM_1 ||
|
|
code == PADDING_STREAM)
|
|
return AVPROBE_SCORE_MAX - 2;
|
|
else
|
|
return 0;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
typedef struct MpegDemuxContext {
|
|
int header_state;
|
|
} MpegDemuxContext;
|
|
|
|
static int mpegps_read_header(AVFormatContext *s,
|
|
AVFormatParameters *ap)
|
|
{
|
|
MpegDemuxContext *m = s->priv_data;
|
|
m->header_state = 0xff;
|
|
s->ctx_flags |= AVFMTCTX_NOHEADER;
|
|
|
|
/* no need to do more */
|
|
return 0;
|
|
}
|
|
|
|
static int64_t get_pts(ByteIOContext *pb, int c)
|
|
{
|
|
int64_t pts;
|
|
int val;
|
|
|
|
if (c < 0)
|
|
c = get_byte(pb);
|
|
pts = (int64_t)((c >> 1) & 0x07) << 30;
|
|
val = get_be16(pb);
|
|
pts |= (int64_t)(val >> 1) << 15;
|
|
val = get_be16(pb);
|
|
pts |= (int64_t)(val >> 1);
|
|
return pts;
|
|
}
|
|
|
|
static int find_next_start_code(ByteIOContext *pb, int *size_ptr,
|
|
uint32_t *header_state)
|
|
{
|
|
unsigned int state, v;
|
|
int val, n;
|
|
|
|
state = *header_state;
|
|
n = *size_ptr;
|
|
while (n > 0) {
|
|
if (url_feof(pb))
|
|
break;
|
|
v = get_byte(pb);
|
|
n--;
|
|
if (state == 0x000001) {
|
|
state = ((state << 8) | v) & 0xffffff;
|
|
val = state;
|
|
goto found;
|
|
}
|
|
state = ((state << 8) | v) & 0xffffff;
|
|
}
|
|
val = -1;
|
|
found:
|
|
*header_state = state;
|
|
*size_ptr = n;
|
|
return val;
|
|
}
|
|
|
|
/* XXX: optimize */
|
|
static int find_prev_start_code(ByteIOContext *pb, int *size_ptr)
|
|
{
|
|
int64_t pos, pos_start;
|
|
int max_size, start_code;
|
|
|
|
max_size = *size_ptr;
|
|
pos_start = url_ftell(pb);
|
|
|
|
/* in order to go faster, we fill the buffer */
|
|
pos = pos_start - 16386;
|
|
if (pos < 0)
|
|
pos = 0;
|
|
url_fseek(pb, pos, SEEK_SET);
|
|
get_byte(pb);
|
|
|
|
pos = pos_start;
|
|
for(;;) {
|
|
pos--;
|
|
if (pos < 0 || (pos_start - pos) >= max_size) {
|
|
start_code = -1;
|
|
goto the_end;
|
|
}
|
|
url_fseek(pb, pos, SEEK_SET);
|
|
start_code = get_be32(pb);
|
|
if ((start_code & 0xffffff00) == 0x100)
|
|
break;
|
|
}
|
|
the_end:
|
|
*size_ptr = pos_start - pos;
|
|
return start_code;
|
|
}
|
|
|
|
/* read the next (or previous) PES header. Return its position in ppos
|
|
(if not NULL), and its start code, pts and dts.
|
|
*/
|
|
static int mpegps_read_pes_header(AVFormatContext *s,
|
|
int64_t *ppos, int *pstart_code,
|
|
int64_t *ppts, int64_t *pdts, int find_next)
|
|
{
|
|
MpegDemuxContext *m = s->priv_data;
|
|
int len, size, startcode, c, flags, header_len;
|
|
int64_t pts, dts, last_pos;
|
|
|
|
last_pos = -1;
|
|
redo:
|
|
if (find_next) {
|
|
/* next start code (should be immediately after) */
|
|
m->header_state = 0xff;
|
|
size = MAX_SYNC_SIZE;
|
|
startcode = find_next_start_code(&s->pb, &size, &m->header_state);
|
|
} else {
|
|
if (last_pos >= 0)
|
|
url_fseek(&s->pb, last_pos, SEEK_SET);
|
|
size = MAX_SYNC_SIZE;
|
|
startcode = find_prev_start_code(&s->pb, &size);
|
|
last_pos = url_ftell(&s->pb) - 4;
|
|
}
|
|
//printf("startcode=%x pos=0x%Lx\n", startcode, url_ftell(&s->pb));
|
|
if (startcode < 0)
|
|
return -EIO;
|
|
if (startcode == PACK_START_CODE)
|
|
goto redo;
|
|
if (startcode == SYSTEM_HEADER_START_CODE)
|
|
goto redo;
|
|
if (startcode == PADDING_STREAM ||
|
|
startcode == PRIVATE_STREAM_2) {
|
|
/* skip them */
|
|
len = get_be16(&s->pb);
|
|
url_fskip(&s->pb, len);
|
|
goto redo;
|
|
}
|
|
/* find matching stream */
|
|
if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
|
|
(startcode >= 0x1e0 && startcode <= 0x1ef) ||
|
|
(startcode == 0x1bd)))
|
|
goto redo;
|
|
if (ppos) {
|
|
*ppos = url_ftell(&s->pb) - 4;
|
|
}
|
|
len = get_be16(&s->pb);
|
|
pts = AV_NOPTS_VALUE;
|
|
dts = AV_NOPTS_VALUE;
|
|
/* stuffing */
|
|
for(;;) {
|
|
if (len < 1)
|
|
goto redo;
|
|
c = get_byte(&s->pb);
|
|
len--;
|
|
/* XXX: for mpeg1, should test only bit 7 */
|
|
if (c != 0xff)
|
|
break;
|
|
}
|
|
if ((c & 0xc0) == 0x40) {
|
|
/* buffer scale & size */
|
|
if (len < 2)
|
|
goto redo;
|
|
get_byte(&s->pb);
|
|
c = get_byte(&s->pb);
|
|
len -= 2;
|
|
}
|
|
if ((c & 0xf0) == 0x20) {
|
|
if (len < 4)
|
|
goto redo;
|
|
dts = pts = get_pts(&s->pb, c);
|
|
len -= 4;
|
|
} else if ((c & 0xf0) == 0x30) {
|
|
if (len < 9)
|
|
goto redo;
|
|
pts = get_pts(&s->pb, c);
|
|
dts = get_pts(&s->pb, -1);
|
|
len -= 9;
|
|
} else if ((c & 0xc0) == 0x80) {
|
|
/* mpeg 2 PES */
|
|
if ((c & 0x30) != 0) {
|
|
/* Encrypted multiplex not handled */
|
|
goto redo;
|
|
}
|
|
flags = get_byte(&s->pb);
|
|
header_len = get_byte(&s->pb);
|
|
len -= 2;
|
|
if (header_len > len)
|
|
goto redo;
|
|
if ((flags & 0xc0) == 0x80) {
|
|
dts = pts = get_pts(&s->pb, -1);
|
|
if (header_len < 5)
|
|
goto redo;
|
|
header_len -= 5;
|
|
len -= 5;
|
|
} if ((flags & 0xc0) == 0xc0) {
|
|
pts = get_pts(&s->pb, -1);
|
|
dts = get_pts(&s->pb, -1);
|
|
if (header_len < 10)
|
|
goto redo;
|
|
header_len -= 10;
|
|
len -= 10;
|
|
}
|
|
len -= header_len;
|
|
while (header_len > 0) {
|
|
get_byte(&s->pb);
|
|
header_len--;
|
|
}
|
|
}
|
|
if (startcode == 0x1bd) {
|
|
if (len < 1)
|
|
goto redo;
|
|
startcode = get_byte(&s->pb);
|
|
len--;
|
|
if (startcode >= 0x80 && startcode <= 0xbf) {
|
|
/* audio: skip header */
|
|
if (len < 3)
|
|
goto redo;
|
|
get_byte(&s->pb);
|
|
get_byte(&s->pb);
|
|
get_byte(&s->pb);
|
|
len -= 3;
|
|
}
|
|
}
|
|
if(dts != AV_NOPTS_VALUE && ppos){
|
|
int i;
|
|
for(i=0; i<s->nb_streams; i++){
|
|
if(startcode == s->streams[i]->id) {
|
|
av_add_index_entry(s->streams[i], *ppos, dts, 0, 0 /* FIXME keyframe? */);
|
|
}
|
|
}
|
|
}
|
|
|
|
*pstart_code = startcode;
|
|
*ppts = pts;
|
|
*pdts = dts;
|
|
return len;
|
|
}
|
|
|
|
static int mpegps_read_packet(AVFormatContext *s,
|
|
AVPacket *pkt)
|
|
{
|
|
AVStream *st;
|
|
int len, startcode, i, type, codec_id;
|
|
int64_t pts, dts, dummy_pos; //dummy_pos is needed for the index building to work
|
|
|
|
redo:
|
|
len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts, 1);
|
|
if (len < 0)
|
|
return len;
|
|
|
|
/* now find stream */
|
|
for(i=0;i<s->nb_streams;i++) {
|
|
st = s->streams[i];
|
|
if (st->id == startcode)
|
|
goto found;
|
|
}
|
|
if (startcode >= 0x1e0 && startcode <= 0x1ef) {
|
|
type = CODEC_TYPE_VIDEO;
|
|
codec_id = CODEC_ID_MPEG2VIDEO;
|
|
} else if (startcode >= 0x1c0 && startcode <= 0x1df) {
|
|
type = CODEC_TYPE_AUDIO;
|
|
codec_id = CODEC_ID_MP2;
|
|
} else if (startcode >= 0x80 && startcode <= 0x9f) {
|
|
type = CODEC_TYPE_AUDIO;
|
|
codec_id = CODEC_ID_AC3;
|
|
} else if (startcode >= 0xa0 && startcode <= 0xbf) {
|
|
type = CODEC_TYPE_AUDIO;
|
|
codec_id = CODEC_ID_PCM_S16BE;
|
|
} else {
|
|
skip:
|
|
/* skip packet */
|
|
url_fskip(&s->pb, len);
|
|
goto redo;
|
|
}
|
|
/* no stream found: add a new stream */
|
|
st = av_new_stream(s, startcode);
|
|
if (!st)
|
|
goto skip;
|
|
st->codec.codec_type = type;
|
|
st->codec.codec_id = codec_id;
|
|
if (codec_id != CODEC_ID_PCM_S16BE)
|
|
st->need_parsing = 1;
|
|
found:
|
|
if (startcode >= 0xa0 && startcode <= 0xbf) {
|
|
int b1, freq;
|
|
|
|
/* for LPCM, we just skip the header and consider it is raw
|
|
audio data */
|
|
if (len <= 3)
|
|
goto skip;
|
|
get_byte(&s->pb); /* emphasis (1), muse(1), reserved(1), frame number(5) */
|
|
b1 = get_byte(&s->pb); /* quant (2), freq(2), reserved(1), channels(3) */
|
|
get_byte(&s->pb); /* dynamic range control (0x80 = off) */
|
|
len -= 3;
|
|
freq = (b1 >> 4) & 3;
|
|
st->codec.sample_rate = lpcm_freq_tab[freq];
|
|
st->codec.channels = 1 + (b1 & 7);
|
|
st->codec.bit_rate = st->codec.channels * st->codec.sample_rate * 2;
|
|
}
|
|
av_new_packet(pkt, len);
|
|
get_buffer(&s->pb, pkt->data, pkt->size);
|
|
pkt->pts = pts;
|
|
pkt->dts = dts;
|
|
pkt->stream_index = st->index;
|
|
#if 0
|
|
printf("%d: pts=%0.3f dts=%0.3f\n",
|
|
pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
static int mpegps_read_close(AVFormatContext *s)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int64_t mpegps_read_dts(AVFormatContext *s, int stream_index,
|
|
int64_t *ppos, int find_next)
|
|
{
|
|
int len, startcode;
|
|
int64_t pos, pts, dts;
|
|
|
|
pos = *ppos;
|
|
#ifdef DEBUG_SEEK
|
|
printf("read_dts: pos=0x%llx next=%d -> ", pos, find_next);
|
|
#endif
|
|
url_fseek(&s->pb, pos, SEEK_SET);
|
|
for(;;) {
|
|
len = mpegps_read_pes_header(s, &pos, &startcode, &pts, &dts, find_next);
|
|
if (len < 0) {
|
|
#ifdef DEBUG_SEEK
|
|
printf("none (ret=%d)\n", len);
|
|
#endif
|
|
return AV_NOPTS_VALUE;
|
|
}
|
|
if (startcode == s->streams[stream_index]->id &&
|
|
dts != AV_NOPTS_VALUE) {
|
|
break;
|
|
}
|
|
if (find_next) {
|
|
url_fskip(&s->pb, len);
|
|
} else {
|
|
url_fseek(&s->pb, pos, SEEK_SET);
|
|
}
|
|
}
|
|
#ifdef DEBUG_SEEK
|
|
printf("pos=0x%llx dts=0x%llx %0.3f\n", pos, dts, dts / 90000.0);
|
|
#endif
|
|
*ppos = pos;
|
|
return dts;
|
|
}
|
|
|
|
static int mpegps_read_seek(AVFormatContext *s,
|
|
int stream_index, int64_t timestamp)
|
|
{
|
|
int64_t pos_min, pos_max, pos, pos_limit;
|
|
int64_t dts_min, dts_max, dts;
|
|
int index, no_change;
|
|
AVStream *st;
|
|
|
|
timestamp = (timestamp * 90000) / AV_TIME_BASE;
|
|
|
|
#ifdef DEBUG_SEEK
|
|
printf("read_seek: %d %0.3f\n", stream_index, timestamp / 90000.0);
|
|
#endif
|
|
|
|
/* XXX: find stream_index by looking at the first PES packet found */
|
|
if (stream_index < 0) {
|
|
stream_index = av_find_default_stream_index(s);
|
|
if (stream_index < 0)
|
|
return -1;
|
|
}
|
|
|
|
dts_max=
|
|
dts_min= AV_NOPTS_VALUE;
|
|
pos_limit= -1; //gcc falsely says it may be uninitalized
|
|
|
|
st= s->streams[stream_index];
|
|
if(st->index_entries){
|
|
AVIndexEntry *e;
|
|
|
|
index= av_index_search_timestamp(st, timestamp);
|
|
e= &st->index_entries[index];
|
|
if(e->timestamp <= timestamp){
|
|
pos_min= e->pos;
|
|
dts_min= e->timestamp;
|
|
#ifdef DEBUG_SEEK
|
|
printf("unsing cached pos_min=0x%llx dts_min=%0.3f\n",
|
|
pos_min,dts_min / 90000.0);
|
|
#endif
|
|
}else{
|
|
assert(index==0);
|
|
}
|
|
index++;
|
|
if(index < st->nb_index_entries){
|
|
e= &st->index_entries[index];
|
|
assert(e->timestamp >= timestamp);
|
|
pos_max= e->pos;
|
|
dts_max= e->timestamp;
|
|
pos_limit= pos_max - e->min_distance;
|
|
#ifdef DEBUG_SEEK
|
|
printf("unsing cached pos_max=0x%llx dts_max=%0.3f\n",
|
|
pos_max,dts_max / 90000.0);
|
|
#endif
|
|
}
|
|
}
|
|
|
|
if(dts_min == AV_NOPTS_VALUE){
|
|
pos_min = 0;
|
|
dts_min = mpegps_read_dts(s, stream_index, &pos_min, 1);
|
|
if (dts_min == AV_NOPTS_VALUE) {
|
|
/* we can reach this case only if no PTS are present in
|
|
the whole stream */
|
|
return -1;
|
|
}
|
|
}
|
|
if(dts_max == AV_NOPTS_VALUE){
|
|
pos_max = url_filesize(url_fileno(&s->pb)) - 1;
|
|
dts_max = mpegps_read_dts(s, stream_index, &pos_max, 0);
|
|
pos_limit= pos_max;
|
|
}
|
|
|
|
no_change=0;
|
|
while (pos_min < pos_limit) {
|
|
#ifdef DEBUG_SEEK
|
|
printf("pos_min=0x%llx pos_max=0x%llx dts_min=%0.3f dts_max=%0.3f\n",
|
|
pos_min, pos_max,
|
|
dts_min / 90000.0, dts_max / 90000.0);
|
|
#endif
|
|
int64_t start_pos;
|
|
assert(pos_limit <= pos_max);
|
|
|
|
if(no_change==0){
|
|
int64_t approximate_keyframe_distance= pos_max - pos_limit;
|
|
// interpolate position (better than dichotomy)
|
|
pos = (int64_t)((double)(pos_max - pos_min) *
|
|
(double)(timestamp - dts_min) /
|
|
(double)(dts_max - dts_min)) + pos_min - approximate_keyframe_distance;
|
|
}else if(no_change==1){
|
|
// bisection, if interpolation failed to change min or max pos last time
|
|
pos = (pos_min + pos_limit)>>1;
|
|
}else{
|
|
// linear search if bisection failed, can only happen if there are very few or no keframes between min/max
|
|
pos=pos_min;
|
|
}
|
|
if(pos <= pos_min)
|
|
pos= pos_min + 1;
|
|
else if(pos > pos_limit)
|
|
pos= pos_limit;
|
|
start_pos= pos;
|
|
|
|
// read the next timestamp
|
|
dts = mpegps_read_dts(s, stream_index, &pos, 1);
|
|
if(pos == pos_max)
|
|
no_change++;
|
|
else
|
|
no_change=0;
|
|
#ifdef DEBUG_SEEK
|
|
printf("%Ld %Ld %Ld / %Ld %Ld %Ld target:%Ld limit:%Ld start:%Ld noc:%d\n", pos_min, pos, pos_max, dts_min, dts, dts_max, timestamp, pos_limit, start_pos, no_change);
|
|
#endif
|
|
assert(dts != AV_NOPTS_VALUE);
|
|
if (timestamp < dts) {
|
|
pos_limit = start_pos - 1;
|
|
pos_max = pos;
|
|
dts_max = dts;
|
|
} else {
|
|
pos_min = pos;
|
|
dts_min = dts;
|
|
/* check if we are lucky */
|
|
if (timestamp == dts)
|
|
break;
|
|
}
|
|
}
|
|
|
|
pos = pos_min;
|
|
#ifdef DEBUG_SEEK
|
|
pos_min = pos;
|
|
dts_min = mpegps_read_dts(s, stream_index, &pos_min, 1);
|
|
pos_min++;
|
|
dts_max = mpegps_read_dts(s, stream_index, &pos_min, 1);
|
|
printf("pos=0x%llx %0.3f<=%0.3f<=%0.3f\n",
|
|
pos, dts_min / 90000.0, timestamp / 90000.0, dts_max / 90000.0);
|
|
#endif
|
|
/* do the seek */
|
|
url_fseek(&s->pb, pos, SEEK_SET);
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_ENCODERS
|
|
static AVOutputFormat mpeg1system_mux = {
|
|
"mpeg",
|
|
"MPEG1 System format",
|
|
"video/mpeg",
|
|
"mpg,mpeg",
|
|
sizeof(MpegMuxContext),
|
|
CODEC_ID_MP2,
|
|
CODEC_ID_MPEG1VIDEO,
|
|
mpeg_mux_init,
|
|
mpeg_mux_write_packet,
|
|
mpeg_mux_end,
|
|
};
|
|
|
|
static AVOutputFormat mpeg1vcd_mux = {
|
|
"vcd",
|
|
"MPEG1 System format (VCD)",
|
|
"video/mpeg",
|
|
NULL,
|
|
sizeof(MpegMuxContext),
|
|
CODEC_ID_MP2,
|
|
CODEC_ID_MPEG1VIDEO,
|
|
mpeg_mux_init,
|
|
mpeg_mux_write_packet,
|
|
mpeg_mux_end,
|
|
};
|
|
|
|
static AVOutputFormat mpeg2vob_mux = {
|
|
"vob",
|
|
"MPEG2 PS format (VOB)",
|
|
"video/mpeg",
|
|
"vob",
|
|
sizeof(MpegMuxContext),
|
|
CODEC_ID_MP2,
|
|
CODEC_ID_MPEG2VIDEO,
|
|
mpeg_mux_init,
|
|
mpeg_mux_write_packet,
|
|
mpeg_mux_end,
|
|
};
|
|
|
|
/* Same as mpeg2vob_mux except that the pack size is 2324 */
|
|
static AVOutputFormat mpeg2svcd_mux = {
|
|
"svcd",
|
|
"MPEG2 PS format (VOB)",
|
|
"video/mpeg",
|
|
"vob",
|
|
sizeof(MpegMuxContext),
|
|
CODEC_ID_MP2,
|
|
CODEC_ID_MPEG2VIDEO,
|
|
mpeg_mux_init,
|
|
mpeg_mux_write_packet,
|
|
mpeg_mux_end,
|
|
};
|
|
|
|
|
|
|
|
#endif //CONFIG_ENCODERS
|
|
|
|
AVInputFormat mpegps_demux = {
|
|
"mpeg",
|
|
"MPEG PS format",
|
|
sizeof(MpegDemuxContext),
|
|
mpegps_probe,
|
|
mpegps_read_header,
|
|
mpegps_read_packet,
|
|
mpegps_read_close,
|
|
mpegps_read_seek,
|
|
};
|
|
|
|
int mpegps_init(void)
|
|
{
|
|
#ifdef CONFIG_ENCODERS
|
|
av_register_output_format(&mpeg1system_mux);
|
|
av_register_output_format(&mpeg1vcd_mux);
|
|
av_register_output_format(&mpeg2vob_mux);
|
|
av_register_output_format(&mpeg2svcd_mux);
|
|
#endif //CONFIG_ENCODERS
|
|
av_register_input_format(&mpegps_demux);
|
|
return 0;
|
|
}
|