diff options
Diffstat (limited to 'ffmpeg1/libavformat/yop.c')
| -rw-r--r-- | ffmpeg1/libavformat/yop.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/ffmpeg1/libavformat/yop.c b/ffmpeg1/libavformat/yop.c new file mode 100644 index 0000000..d1c0129 --- /dev/null +++ b/ffmpeg1/libavformat/yop.c @@ -0,0 +1,229 @@ +/* + * 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/channel_layout.h" +#include "libavutil/intreadwrite.h" +#include "avformat.h" +#include "internal.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[2]<10 && + probe_packet->buf[3]<10 && + probe_packet->buf[6] && + probe_packet->buf[7] && + !(probe_packet->buf[8] & 1) && + !(probe_packet->buf[10] & 1) && + AV_RL16(probe_packet->buf + 12 + 6) >= 920 && + AV_RL16(probe_packet->buf + 12 + 6) < probe_packet->buf[12] * 3 + 4 + probe_packet->buf[7] * 2048 + ) + return AVPROBE_SCORE_MAX * 3 / 4; + + return 0; +} + +static int yop_read_header(AVFormatContext *s) +{ + YopDecContext *yop = s->priv_data; + AVIOContext *pb = s->pb; + + AVCodecContext *audio_dec, *video_dec; + AVStream *audio_stream, *video_stream; + + int frame_rate, ret; + + audio_stream = avformat_new_stream(s, NULL); + video_stream = avformat_new_stream(s, NULL); + if (!audio_stream || !video_stream) + return AVERROR(ENOMEM); + + // 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 = AV_CODEC_ID_ADPCM_IMA_APC; + audio_dec->channels = 1; + audio_dec->channel_layout = AV_CH_LAYOUT_MONO; + audio_dec->sample_rate = 22050; + + // Video + video_dec = video_stream->codec; + video_dec->codec_type = AVMEDIA_TYPE_VIDEO; + video_dec->codec_id = AV_CODEC_ID_YOP; + + avio_skip(pb, 6); + + frame_rate = avio_r8(pb); + yop->frame_size = avio_r8(pb) * 2048; + video_dec->width = avio_rl16(pb); + video_dec->height = avio_rl16(pb); + + video_stream->sample_aspect_ratio = (AVRational){1, 2}; + + ret = avio_read(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); + + video_dec->bit_rate = 8 * (yop->frame_size - yop->audio_block_length) * frame_rate; + + // 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; + } + + avio_seek(pb, 2048, SEEK_SET); + + avpriv_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; + AVIOContext *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 |= AV_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 = avio_tell(pb); + + ret = avio_read(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; + + avio_skip(pb, yop->audio_block_length - ret); + + ret = avio_read(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; + + if (!stream_index) + return -1; + + pos_min = s->data_offset; + pos_max = avio_size(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; + + if (avio_seek(s->pb, frame_pos, SEEK_SET) < 0) + return -1; + + av_free_packet(&yop->video_packet); + yop->odd_frame = timestamp & 1; + + return 0; +} + +AVInputFormat ff_yop_demuxer = { + .name = "yop", + .long_name = NULL_IF_CONFIG_SMALL("Psygnosis YOP"), + .priv_data_size = sizeof(YopDecContext), + .read_probe = yop_probe, + .read_header = yop_read_header, + .read_packet = yop_read_packet, + .read_close = yop_read_close, + .read_seek = yop_read_seek, + .extensions = "yop", + .flags = AVFMT_GENERIC_INDEX, +}; |