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ffmpeg/libavformat/bethsoftvid.c

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/*
* Bethsoft VID format Demuxer
* Copyright (c) 2007 Nicholas Tung
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* @brief Bethesda Softworks VID (.vid) file demuxer
* @author Nicholas Tung [ntung (at. ntung com] (2007-03)
* @see http://wiki.multimedia.cx/index.php?title=Bethsoft_VID
* @see http://www.svatopluk.com/andux/docs/dfvid.html
*/
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#include "internal.h"
#include "libavcodec/bethsoftvideo.h"
#define BVID_PALETTE_SIZE 3 * 256
#define DEFAULT_SAMPLE_RATE 11111
typedef struct BVID_DemuxContext
{
int nframes;
int sample_rate; /**< audio sample rate */
int width; /**< video width */
int height; /**< video height */
/** delay value between frames, added to individual frame delay.
* custom units, which will be added to other custom units (~=16ms according
* to free, unofficial documentation) */
int bethsoft_global_delay;
int video_index; /**< video stream index */
int audio_index; /**< audio stream index */
uint8_t *palette;
int is_finished;
} BVID_DemuxContext;
static int vid_probe(AVProbeData *p)
{
// little endian VID tag, file starts with "VID\0"
if (AV_RL32(p->buf) != MKTAG('V', 'I', 'D', 0))
return 0;
return AVPROBE_SCORE_MAX;
}
static int vid_read_header(AVFormatContext *s)
{
BVID_DemuxContext *vid = s->priv_data;
AVIOContext *pb = s->pb;
/* load main header. Contents:
* bytes: 'V' 'I' 'D'
* int16s: always_512, nframes, width, height, delay, always_14
*/
avio_skip(pb, 5);
vid->nframes = avio_rl16(pb);
vid->width = avio_rl16(pb);
vid->height = avio_rl16(pb);
vid->bethsoft_global_delay = avio_rl16(pb);
avio_rl16(pb);
// wait until the first packet to create each stream
vid->video_index = -1;
vid->audio_index = -1;
vid->sample_rate = DEFAULT_SAMPLE_RATE;
s->ctx_flags |= AVFMTCTX_NOHEADER;
return 0;
}
#define BUFFER_PADDING_SIZE 1000
static int read_frame(BVID_DemuxContext *vid, AVIOContext *pb, AVPacket *pkt,
uint8_t block_type, AVFormatContext *s)
{
uint8_t * vidbuf_start = NULL;
int vidbuf_nbytes = 0;
int code;
int bytes_copied = 0;
int position, duration, npixels;
unsigned int vidbuf_capacity;
int ret = 0;
AVStream *st;
if (vid->video_index < 0) {
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
vid->video_index = st->index;
if (vid->audio_index < 0) {
av_log_ask_for_sample(s, "No audio packet before first video "
"packet. Using default video time base.\n");
}
avpriv_set_pts_info(st, 64, 185, vid->sample_rate);
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
st->codec->codec_id = AV_CODEC_ID_BETHSOFTVID;
st->codec->width = vid->width;
st->codec->height = vid->height;
}
st = s->streams[vid->video_index];
npixels = st->codec->width * st->codec->height;
vidbuf_start = av_malloc(vidbuf_capacity = BUFFER_PADDING_SIZE);
if(!vidbuf_start)
return AVERROR(ENOMEM);
// save the file position for the packet, include block type
position = avio_tell(pb) - 1;
vidbuf_start[vidbuf_nbytes++] = block_type;
// get the current packet duration
duration = vid->bethsoft_global_delay + avio_rl16(pb);
// set the y offset if it exists (decoder header data should be in data section)
if(block_type == VIDEO_YOFF_P_FRAME){
if (avio_read(pb, &vidbuf_start[vidbuf_nbytes], 2) != 2) {
ret = AVERROR(EIO);
goto fail;
}
vidbuf_nbytes += 2;
}
do{
vidbuf_start = av_fast_realloc(vidbuf_start, &vidbuf_capacity, vidbuf_nbytes + BUFFER_PADDING_SIZE);
if(!vidbuf_start)
return AVERROR(ENOMEM);
code = avio_r8(pb);
vidbuf_start[vidbuf_nbytes++] = code;
if(code >= 0x80){ // rle sequence
if(block_type == VIDEO_I_FRAME)
vidbuf_start[vidbuf_nbytes++] = avio_r8(pb);
} else if(code){ // plain sequence
if (avio_read(pb, &vidbuf_start[vidbuf_nbytes], code) != code) {
ret = AVERROR(EIO);
goto fail;
}
vidbuf_nbytes += code;
}
bytes_copied += code & 0x7F;
if(bytes_copied == npixels){ // sometimes no stop character is given, need to keep track of bytes copied
// may contain a 0 byte even if read all pixels
if(avio_r8(pb))
avio_seek(pb, -1, SEEK_CUR);
break;
}
if (bytes_copied > npixels) {
ret = AVERROR_INVALIDDATA;
goto fail;
}
} while(code);
// copy data into packet
if ((ret = av_new_packet(pkt, vidbuf_nbytes)) < 0)
goto fail;
memcpy(pkt->data, vidbuf_start, vidbuf_nbytes);
av_free(vidbuf_start);
pkt->pos = position;
pkt->stream_index = vid->video_index;
pkt->duration = duration;
if (block_type == VIDEO_I_FRAME)
pkt->flags |= AV_PKT_FLAG_KEY;
/* if there is a new palette available, add it to packet side data */
if (vid->palette) {
uint8_t *pdata = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE,
BVID_PALETTE_SIZE);
if (pdata)
memcpy(pdata, vid->palette, BVID_PALETTE_SIZE);
av_freep(&vid->palette);
}
vid->nframes--; // used to check if all the frames were read
return 0;
fail:
av_free(vidbuf_start);
return ret;
}
static int vid_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
BVID_DemuxContext *vid = s->priv_data;
AVIOContext *pb = s->pb;
unsigned char block_type;
int audio_length;
int ret_value;
if(vid->is_finished || url_feof(pb))
return AVERROR(EIO);
block_type = avio_r8(pb);
switch(block_type){
case PALETTE_BLOCK:
if (vid->palette) {
av_log(s, AV_LOG_WARNING, "discarding unused palette\n");
av_freep(&vid->palette);
}
vid->palette = av_malloc(BVID_PALETTE_SIZE);
if (!vid->palette)
return AVERROR(ENOMEM);
if (avio_read(pb, vid->palette, BVID_PALETTE_SIZE) != BVID_PALETTE_SIZE) {
av_freep(&vid->palette);
return AVERROR(EIO);
}
return vid_read_packet(s, pkt);
case FIRST_AUDIO_BLOCK:
avio_rl16(pb);
// soundblaster DAC used for sample rate, as on specification page (link above)
vid->sample_rate = 1000000 / (256 - avio_r8(pb));
case AUDIO_BLOCK:
if (vid->audio_index < 0) {
AVStream *st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
vid->audio_index = st->index;
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = AV_CODEC_ID_PCM_U8;
st->codec->channels = 1;
st->codec->bits_per_coded_sample = 8;
st->codec->sample_rate = vid->sample_rate;
st->codec->bit_rate = 8 * st->codec->sample_rate;
st->start_time = 0;
avpriv_set_pts_info(st, 64, 1, vid->sample_rate);
}
audio_length = avio_rl16(pb);
if ((ret_value = av_get_packet(pb, pkt, audio_length)) != audio_length) {
if (ret_value < 0)
return ret_value;
av_log(s, AV_LOG_ERROR, "incomplete audio block\n");
return AVERROR(EIO);
}
pkt->stream_index = vid->audio_index;
pkt->duration = audio_length;
pkt->flags |= AV_PKT_FLAG_KEY;
return 0;
case VIDEO_P_FRAME:
case VIDEO_YOFF_P_FRAME:
case VIDEO_I_FRAME:
return read_frame(vid, pb, pkt, block_type, s);
case EOF_BLOCK:
if(vid->nframes != 0)
av_log(s, AV_LOG_VERBOSE, "reached terminating character but not all frames read.\n");
vid->is_finished = 1;
return AVERROR(EIO);
default:
av_log(s, AV_LOG_ERROR, "unknown block (character = %c, decimal = %d, hex = %x)!!!\n",
block_type, block_type, block_type);
return AVERROR_INVALIDDATA;
}
}
static int vid_read_close(AVFormatContext *s)
{
BVID_DemuxContext *vid = s->priv_data;
av_freep(&vid->palette);
return 0;
}
AVInputFormat ff_bethsoftvid_demuxer = {
.name = "bethsoftvid",
.long_name = NULL_IF_CONFIG_SMALL("Bethesda Softworks VID"),
.priv_data_size = sizeof(BVID_DemuxContext),
.read_probe = vid_probe,
.read_header = vid_read_header,
.read_packet = vid_read_packet,
.read_close = vid_read_close,
};
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