ffmpeg/libavformat/yop.c
Stefano Sabatini 72415b2adb Define AVMediaType enum, and use it instead of enum CodecType, which
is deprecated and will be dropped at the next major bump.

Originally committed as revision 22735 to svn://svn.ffmpeg.org/ffmpeg/trunk
2010-03-30 23:30:55 +00:00

217 lines
6.2 KiB
C

/**
* @file libavformat/yop.c
* Psygnosis YOP demuxer
*
* Copyright (C) 2010 Mohamed Naufal Basheer <naufal11@gmail.com>
* derived from the code by
* Copyright (C) 2009 Thomas P. Higdon <thomas.p.higdon@gmail.com>
*
* 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
*/
#include "libavutil/intreadwrite.h"
#include "avformat.h"
typedef struct yop_dec_context {
AVPacket video_packet;
int odd_frame;
int frame_size;
int audio_block_length;
int palette_size;
} YopDecContext;
static int yop_probe(AVProbeData *probe_packet)
{
if (AV_RB16(probe_packet->buf) == AV_RB16("YO") &&
probe_packet->buf[6] &&
probe_packet->buf[7] &&
!(probe_packet->buf[8] & 1) &&
!(probe_packet->buf[10] & 1))
return AVPROBE_SCORE_MAX * 3 / 4;
return 0;
}
static int yop_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
YopDecContext *yop = s->priv_data;
ByteIOContext *pb = s->pb;
AVCodecContext *audio_dec, *video_dec;
AVStream *audio_stream, *video_stream;
int frame_rate, ret;
audio_stream = av_new_stream(s, 0);
video_stream = av_new_stream(s, 1);
// Extra data that will be passed to the decoder
video_stream->codec->extradata_size = 8;
video_stream->codec->extradata = av_mallocz(video_stream->codec->extradata_size +
FF_INPUT_BUFFER_PADDING_SIZE);
if (!video_stream->codec->extradata)
return AVERROR(ENOMEM);
// Audio
audio_dec = audio_stream->codec;
audio_dec->codec_type = AVMEDIA_TYPE_AUDIO;
audio_dec->codec_id = CODEC_ID_ADPCM_IMA_WS;
audio_dec->channels = 1;
audio_dec->sample_rate = 22050;
// Video
video_dec = video_stream->codec;
video_dec->codec_type = AVMEDIA_TYPE_VIDEO;
video_dec->codec_id = CODEC_ID_YOP;
url_fskip(pb, 6);
frame_rate = get_byte(pb);
yop->frame_size = get_byte(pb) * 2048;
video_dec->width = get_le16(pb);
video_dec->height = get_le16(pb);
video_stream->sample_aspect_ratio = (AVRational){1, 2};
ret = get_buffer(pb, video_dec->extradata, 8);
if (ret < 8)
return ret < 0 ? ret : AVERROR_EOF;
yop->palette_size = video_dec->extradata[0] * 3 + 4;
yop->audio_block_length = AV_RL16(video_dec->extradata + 6);
// 1840 samples per frame, 1 nibble per sample; hence 1840/2 = 920
if (yop->audio_block_length < 920 ||
yop->audio_block_length + yop->palette_size >= yop->frame_size) {
av_log(s, AV_LOG_ERROR, "YOP has invalid header\n");
return AVERROR_INVALIDDATA;
}
url_fseek(pb, 2048, SEEK_SET);
av_set_pts_info(video_stream, 32, 1, frame_rate);
return 0;
}
static int yop_read_packet(AVFormatContext *s, AVPacket *pkt)
{
YopDecContext *yop = s->priv_data;
ByteIOContext *pb = s->pb;
int ret;
int actual_video_data_size = yop->frame_size -
yop->audio_block_length - yop->palette_size;
yop->video_packet.stream_index = 1;
if (yop->video_packet.data) {
*pkt = yop->video_packet;
yop->video_packet.data = NULL;
yop->video_packet.size = 0;
pkt->data[0] = yop->odd_frame;
pkt->flags |= PKT_FLAG_KEY;
yop->odd_frame ^= 1;
return pkt->size;
}
ret = av_new_packet(&yop->video_packet,
yop->frame_size - yop->audio_block_length);
if (ret < 0)
return ret;
yop->video_packet.pos = url_ftell(pb);
ret = get_buffer(pb, yop->video_packet.data, yop->palette_size);
if (ret < 0) {
goto err_out;
}else if (ret < yop->palette_size) {
ret = AVERROR_EOF;
goto err_out;
}
ret = av_get_packet(pb, pkt, 920);
if (ret < 0)
goto err_out;
// Set position to the start of the frame
pkt->pos = yop->video_packet.pos;
url_fskip(pb, yop->audio_block_length - ret);
ret = get_buffer(pb, yop->video_packet.data + yop->palette_size,
actual_video_data_size);
if (ret < 0)
goto err_out;
else if (ret < actual_video_data_size)
av_shrink_packet(&yop->video_packet, yop->palette_size + ret);
// Arbitrarily return the audio data first
return yop->audio_block_length;
err_out:
av_free_packet(&yop->video_packet);
return ret;
}
static int yop_read_close(AVFormatContext *s)
{
YopDecContext *yop = s->priv_data;
av_free_packet(&yop->video_packet);
return 0;
}
static int yop_read_seek(AVFormatContext *s, int stream_index,
int64_t timestamp, int flags)
{
YopDecContext *yop = s->priv_data;
int64_t frame_pos, pos_min, pos_max;
int frame_count;
av_free_packet(&yop->video_packet);
if (!stream_index)
return -1;
pos_min = s->data_offset;
pos_max = url_fsize(s->pb) - yop->frame_size;
frame_count = (pos_max - pos_min) / yop->frame_size;
timestamp = FFMAX(0, FFMIN(frame_count, timestamp));
frame_pos = timestamp * yop->frame_size + pos_min;
yop->odd_frame = timestamp & 1;
url_fseek(s->pb, frame_pos, SEEK_SET);
return 0;
}
AVInputFormat yop_demuxer = {
"yop",
NULL_IF_CONFIG_SMALL("Psygnosis YOP Format"),
sizeof(YopDecContext),
yop_probe,
yop_read_header,
yop_read_packet,
yop_read_close,
yop_read_seek,
.extensions = "yop",
.flags = AVFMT_GENERIC_INDEX,
};