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430 lines
13 KiB
C
430 lines
13 KiB
C
/*
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* AVC helper functions for muxers
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* Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg 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 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg 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 FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "libavutil/intreadwrite.h"
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#include "libavcodec/h264.h"
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#include "libavcodec/get_bits.h"
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#include "avformat.h"
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#include "avio.h"
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#include "avc.h"
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static const uint8_t *ff_avc_find_startcode_internal(const uint8_t *p, const uint8_t *end)
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{
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const uint8_t *a = p + 4 - ((intptr_t)p & 3);
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for (end -= 3; p < a && p < end; p++) {
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if (p[0] == 0 && p[1] == 0 && p[2] == 1)
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return p;
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}
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for (end -= 3; p < end; p += 4) {
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uint32_t x = *(const uint32_t*)p;
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// if ((x - 0x01000100) & (~x) & 0x80008000) // little endian
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// if ((x - 0x00010001) & (~x) & 0x00800080) // big endian
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if ((x - 0x01010101) & (~x) & 0x80808080) { // generic
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if (p[1] == 0) {
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if (p[0] == 0 && p[2] == 1)
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return p;
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if (p[2] == 0 && p[3] == 1)
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return p+1;
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}
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if (p[3] == 0) {
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if (p[2] == 0 && p[4] == 1)
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return p+2;
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if (p[4] == 0 && p[5] == 1)
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return p+3;
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}
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}
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}
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for (end += 3; p < end; p++) {
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if (p[0] == 0 && p[1] == 0 && p[2] == 1)
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return p;
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}
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return end + 3;
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}
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const uint8_t *ff_avc_find_startcode(const uint8_t *p, const uint8_t *end){
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const uint8_t *out= ff_avc_find_startcode_internal(p, end);
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if(p<out && out<end && !out[-1]) out--;
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return out;
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}
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int ff_avc_parse_nal_units(AVIOContext *pb, const uint8_t *buf_in, int size)
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{
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const uint8_t *p = buf_in;
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const uint8_t *end = p + size;
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const uint8_t *nal_start, *nal_end;
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size = 0;
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nal_start = ff_avc_find_startcode(p, end);
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for (;;) {
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while (nal_start < end && !*(nal_start++));
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if (nal_start == end)
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break;
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nal_end = ff_avc_find_startcode(nal_start, end);
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avio_wb32(pb, nal_end - nal_start);
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avio_write(pb, nal_start, nal_end - nal_start);
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size += 4 + nal_end - nal_start;
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nal_start = nal_end;
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}
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return size;
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}
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int ff_avc_parse_nal_units_buf(const uint8_t *buf_in, uint8_t **buf, int *size)
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{
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AVIOContext *pb;
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int ret = avio_open_dyn_buf(&pb);
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if(ret < 0)
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return ret;
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ff_avc_parse_nal_units(pb, buf_in, *size);
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av_freep(buf);
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*size = avio_close_dyn_buf(pb, buf);
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return 0;
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}
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int ff_isom_write_avcc(AVIOContext *pb, const uint8_t *data, int len)
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{
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AVIOContext *sps_pb = NULL, *pps_pb = NULL;
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uint8_t *buf = NULL, *end, *start = NULL;
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uint8_t *sps = NULL, *pps = NULL;
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uint32_t sps_size = 0, pps_size = 0;
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int ret, nb_sps = 0, nb_pps = 0;
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if (len <= 6)
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return AVERROR_INVALIDDATA;
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/* check for H.264 start code */
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if (AV_RB32(data) != 0x00000001 &&
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AV_RB24(data) != 0x000001) {
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avio_write(pb, data, len);
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return 0;
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}
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ret = ff_avc_parse_nal_units_buf(data, &buf, &len);
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if (ret < 0)
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return ret;
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start = buf;
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end = buf + len;
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ret = avio_open_dyn_buf(&sps_pb);
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if (ret < 0)
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goto fail;
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ret = avio_open_dyn_buf(&pps_pb);
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if (ret < 0)
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goto fail;
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/* look for sps and pps */
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while (end - buf > 4) {
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uint32_t size;
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uint8_t nal_type;
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size = FFMIN(AV_RB32(buf), end - buf - 4);
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buf += 4;
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nal_type = buf[0] & 0x1f;
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if (nal_type == 7) { /* SPS */
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nb_sps++;
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if (size > UINT16_MAX || nb_sps >= H264_MAX_SPS_COUNT) {
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ret = AVERROR_INVALIDDATA;
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goto fail;
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}
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avio_wb16(sps_pb, size);
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avio_write(sps_pb, buf, size);
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} else if (nal_type == 8) { /* PPS */
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nb_pps++;
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if (size > UINT16_MAX || nb_pps >= H264_MAX_PPS_COUNT) {
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ret = AVERROR_INVALIDDATA;
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goto fail;
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}
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avio_wb16(pps_pb, size);
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avio_write(pps_pb, buf, size);
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}
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buf += size;
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}
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sps_size = avio_close_dyn_buf(sps_pb, &sps);
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pps_size = avio_close_dyn_buf(pps_pb, &pps);
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if (sps_size < 6 || !pps_size) {
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ret = AVERROR_INVALIDDATA;
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goto fail;
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}
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avio_w8(pb, 1); /* version */
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avio_w8(pb, sps[3]); /* profile */
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avio_w8(pb, sps[4]); /* profile compat */
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avio_w8(pb, sps[5]); /* level */
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avio_w8(pb, 0xff); /* 6 bits reserved (111111) + 2 bits nal size length - 1 (11) */
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avio_w8(pb, 0xe0 | nb_sps); /* 3 bits reserved (111) + 5 bits number of sps */
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avio_write(pb, sps, sps_size);
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avio_w8(pb, nb_pps); /* number of pps */
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avio_write(pb, pps, pps_size);
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fail:
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if (!sps)
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avio_close_dyn_buf(sps_pb, &sps);
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if (!pps)
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avio_close_dyn_buf(pps_pb, &pps);
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av_free(sps);
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av_free(pps);
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av_free(start);
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return ret;
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}
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int ff_avc_write_annexb_extradata(const uint8_t *in, uint8_t **buf, int *size)
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{
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uint16_t sps_size, pps_size;
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uint8_t *out;
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int out_size;
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*buf = NULL;
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if (*size >= 4 && (AV_RB32(in) == 0x00000001 || AV_RB24(in) == 0x000001))
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return 0;
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if (*size < 11 || in[0] != 1)
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return AVERROR_INVALIDDATA;
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sps_size = AV_RB16(&in[6]);
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if (11 + sps_size > *size)
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return AVERROR_INVALIDDATA;
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pps_size = AV_RB16(&in[9 + sps_size]);
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if (11 + sps_size + pps_size > *size)
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return AVERROR_INVALIDDATA;
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out_size = 8 + sps_size + pps_size;
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out = av_mallocz(out_size + AV_INPUT_BUFFER_PADDING_SIZE);
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if (!out)
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return AVERROR(ENOMEM);
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AV_WB32(&out[0], 0x00000001);
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memcpy(out + 4, &in[8], sps_size);
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AV_WB32(&out[4 + sps_size], 0x00000001);
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memcpy(out + 8 + sps_size, &in[11 + sps_size], pps_size);
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*buf = out;
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*size = out_size;
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return 0;
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}
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const uint8_t *ff_avc_mp4_find_startcode(const uint8_t *start,
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const uint8_t *end,
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int nal_length_size)
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{
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unsigned int res = 0;
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if (end - start < nal_length_size)
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return NULL;
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while (nal_length_size--)
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res = (res << 8) | *start++;
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if (res > end - start)
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return NULL;
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return start + res;
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}
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uint8_t *ff_nal_unit_extract_rbsp(const uint8_t *src, uint32_t src_len,
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uint32_t *dst_len, int header_len)
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{
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uint8_t *dst;
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uint32_t i, len;
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dst = av_malloc(src_len + AV_INPUT_BUFFER_PADDING_SIZE);
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if (!dst)
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return NULL;
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/* NAL unit header */
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i = len = 0;
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while (i < header_len && i < src_len)
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dst[len++] = src[i++];
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while (i + 2 < src_len)
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if (!src[i] && !src[i + 1] && src[i + 2] == 3) {
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dst[len++] = src[i++];
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dst[len++] = src[i++];
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i++; // remove emulation_prevention_three_byte
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} else
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dst[len++] = src[i++];
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while (i < src_len)
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dst[len++] = src[i++];
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memset(dst + len, 0, AV_INPUT_BUFFER_PADDING_SIZE);
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*dst_len = len;
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return dst;
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}
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static const AVRational avc_sample_aspect_ratio[17] = {
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{ 0, 1 },
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{ 1, 1 },
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{ 12, 11 },
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{ 10, 11 },
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{ 16, 11 },
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{ 40, 33 },
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{ 24, 11 },
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{ 20, 11 },
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{ 32, 11 },
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{ 80, 33 },
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{ 18, 11 },
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{ 15, 11 },
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{ 64, 33 },
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{ 160, 99 },
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{ 4, 3 },
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{ 3, 2 },
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{ 2, 1 },
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};
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static inline int get_ue_golomb(GetBitContext *gb) {
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int i;
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for (i = 0; i < 32 && !get_bits1(gb); i++)
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;
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return get_bitsz(gb, i) + (1 << i) - 1;
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}
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static inline int get_se_golomb(GetBitContext *gb) {
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int v = get_ue_golomb(gb) + 1;
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int sign = -(v & 1);
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return ((v >> 1) ^ sign) - sign;
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}
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H264SequenceParameterSet *ff_avc_decode_sps(const uint8_t *buf, int buf_size)
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{
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int i, j, ret, rbsp_size, aspect_ratio_idc, pic_order_cnt_type;
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int num_ref_frames_in_pic_order_cnt_cycle;
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int delta_scale, lastScale = 8, nextScale = 8;
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int sizeOfScalingList;
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H264SequenceParameterSet *sps = NULL;
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GetBitContext gb;
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uint8_t *rbsp_buf;
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rbsp_buf = ff_nal_unit_extract_rbsp(buf, buf_size, &rbsp_size, 0);
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if (!rbsp_buf)
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return NULL;
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ret = init_get_bits8(&gb, rbsp_buf, rbsp_size);
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if (ret < 0)
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goto end;
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sps = av_mallocz(sizeof(*sps));
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if (!sps)
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goto end;
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sps->profile_idc = get_bits(&gb, 8);
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sps->constraint_set_flags |= get_bits1(&gb) << 0; // constraint_set0_flag
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sps->constraint_set_flags |= get_bits1(&gb) << 1; // constraint_set1_flag
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sps->constraint_set_flags |= get_bits1(&gb) << 2; // constraint_set2_flag
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sps->constraint_set_flags |= get_bits1(&gb) << 3; // constraint_set3_flag
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sps->constraint_set_flags |= get_bits1(&gb) << 4; // constraint_set4_flag
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sps->constraint_set_flags |= get_bits1(&gb) << 5; // constraint_set5_flag
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skip_bits(&gb, 2); // reserved_zero_2bits
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sps->level_idc = get_bits(&gb, 8);
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sps->id = get_ue_golomb(&gb);
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if (sps->profile_idc == 100 || sps->profile_idc == 110 ||
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sps->profile_idc == 122 || sps->profile_idc == 244 || sps->profile_idc == 44 ||
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sps->profile_idc == 83 || sps->profile_idc == 86 || sps->profile_idc == 118 ||
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sps->profile_idc == 128 || sps->profile_idc == 138 || sps->profile_idc == 139 ||
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sps->profile_idc == 134) {
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sps->chroma_format_idc = get_ue_golomb(&gb); // chroma_format_idc
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if (sps->chroma_format_idc == 3) {
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skip_bits1(&gb); // separate_colour_plane_flag
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}
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sps->bit_depth_luma = get_ue_golomb(&gb) + 8;
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get_ue_golomb(&gb); // bit_depth_chroma_minus8
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skip_bits1(&gb); // qpprime_y_zero_transform_bypass_flag
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if (get_bits1(&gb)) { // seq_scaling_matrix_present_flag
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for (i = 0; i < ((sps->chroma_format_idc != 3) ? 8 : 12); i++) {
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if (!get_bits1(&gb)) // seq_scaling_list_present_flag
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continue;
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lastScale = 8;
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nextScale = 8;
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sizeOfScalingList = i < 6 ? 16 : 64;
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for (j = 0; j < sizeOfScalingList; j++) {
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if (nextScale != 0) {
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delta_scale = get_se_golomb(&gb);
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nextScale = (lastScale + delta_scale) & 0xff;
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}
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lastScale = nextScale == 0 ? lastScale : nextScale;
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}
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}
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}
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} else {
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sps->chroma_format_idc = 1;
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sps->bit_depth_luma = 8;
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}
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get_ue_golomb(&gb); // log2_max_frame_num_minus4
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pic_order_cnt_type = get_ue_golomb(&gb);
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if (pic_order_cnt_type == 0) {
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get_ue_golomb(&gb); // log2_max_pic_order_cnt_lsb_minus4
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} else if (pic_order_cnt_type == 1) {
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skip_bits1(&gb); // delta_pic_order_always_zero
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get_se_golomb(&gb); // offset_for_non_ref_pic
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get_se_golomb(&gb); // offset_for_top_to_bottom_field
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num_ref_frames_in_pic_order_cnt_cycle = get_ue_golomb(&gb);
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for (i = 0; i < num_ref_frames_in_pic_order_cnt_cycle; i++)
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get_se_golomb(&gb); // offset_for_ref_frame
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}
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get_ue_golomb(&gb); // max_num_ref_frames
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skip_bits1(&gb); // gaps_in_frame_num_value_allowed_flag
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get_ue_golomb(&gb); // pic_width_in_mbs_minus1
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get_ue_golomb(&gb); // pic_height_in_map_units_minus1
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sps->frame_mbs_only_flag = get_bits1(&gb);
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if (!sps->frame_mbs_only_flag)
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skip_bits1(&gb); // mb_adaptive_frame_field_flag
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skip_bits1(&gb); // direct_8x8_inference_flag
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if (get_bits1(&gb)) { // frame_cropping_flag
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get_ue_golomb(&gb); // frame_crop_left_offset
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get_ue_golomb(&gb); // frame_crop_right_offset
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get_ue_golomb(&gb); // frame_crop_top_offset
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get_ue_golomb(&gb); // frame_crop_bottom_offset
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}
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if (get_bits1(&gb)) { // vui_parameters_present_flag
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if (get_bits1(&gb)) { // aspect_ratio_info_present_flag
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aspect_ratio_idc = get_bits(&gb, 8);
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if (aspect_ratio_idc == 0xff) {
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sps->sar.num = get_bits(&gb, 16);
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sps->sar.den = get_bits(&gb, 16);
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} else if (aspect_ratio_idc < FF_ARRAY_ELEMS(avc_sample_aspect_ratio)) {
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sps->sar = avc_sample_aspect_ratio[aspect_ratio_idc];
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}
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}
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}
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if (!sps->sar.den) {
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sps->sar.num = 1;
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sps->sar.den = 1;
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}
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end:
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av_free(rbsp_buf);
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return sps;
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}
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