diff options
Diffstat (limited to 'ffmpeg1/libavformat/tmv.c')
| -rw-r--r-- | ffmpeg1/libavformat/tmv.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/ffmpeg1/libavformat/tmv.c b/ffmpeg1/libavformat/tmv.c new file mode 100644 index 0000000..8be4dbf --- /dev/null +++ b/ffmpeg1/libavformat/tmv.c @@ -0,0 +1,199 @@ +/* + * 8088flex TMV file demuxer + * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu> + * + * 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 + * 8088flex TMV file demuxer + * @author Daniel Verkamp + * @see http://www.oldskool.org/pc/8088_Corruption + */ + +#include "libavutil/channel_layout.h" +#include "libavutil/intreadwrite.h" +#include "avformat.h" +#include "internal.h" + +enum { + TMV_PADDING = 0x01, + TMV_STEREO = 0x02, +}; + +#define TMV_TAG MKTAG('T', 'M', 'A', 'V') + +typedef struct TMVContext { + unsigned audio_chunk_size; + unsigned video_chunk_size; + unsigned padding; + unsigned stream_index; +} TMVContext; + +#define TMV_HEADER_SIZE 12 + +#define PROBE_MIN_SAMPLE_RATE 5000 +#define PROBE_MAX_FPS 120 +#define PROBE_MIN_AUDIO_SIZE (PROBE_MIN_SAMPLE_RATE / PROBE_MAX_FPS) + +static int tmv_probe(AVProbeData *p) +{ + if (AV_RL32(p->buf) == TMV_TAG && + AV_RL16(p->buf+4) >= PROBE_MIN_SAMPLE_RATE && + AV_RL16(p->buf+6) >= PROBE_MIN_AUDIO_SIZE && + !p->buf[8] && // compression method + p->buf[9] && // char cols + p->buf[10]) // char rows + return AVPROBE_SCORE_MAX / + ((p->buf[9] == 40 && p->buf[10] == 25) ? 1 : 4); + return 0; +} + +static int tmv_read_header(AVFormatContext *s) +{ + TMVContext *tmv = s->priv_data; + AVIOContext *pb = s->pb; + AVStream *vst, *ast; + AVRational fps; + unsigned comp_method, char_cols, char_rows, features; + + if (avio_rl32(pb) != TMV_TAG) + return -1; + + if (!(vst = avformat_new_stream(s, NULL))) + return AVERROR(ENOMEM); + + if (!(ast = avformat_new_stream(s, NULL))) + return AVERROR(ENOMEM); + + ast->codec->sample_rate = avio_rl16(pb); + if (!ast->codec->sample_rate) { + av_log(s, AV_LOG_ERROR, "invalid sample rate\n"); + return -1; + } + + tmv->audio_chunk_size = avio_rl16(pb); + if (!tmv->audio_chunk_size) { + av_log(s, AV_LOG_ERROR, "invalid audio chunk size\n"); + return -1; + } + + comp_method = avio_r8(pb); + if (comp_method) { + av_log(s, AV_LOG_ERROR, "unsupported compression method %d\n", + comp_method); + return -1; + } + + char_cols = avio_r8(pb); + char_rows = avio_r8(pb); + tmv->video_chunk_size = char_cols * char_rows * 2; + + features = avio_r8(pb); + if (features & ~(TMV_PADDING | TMV_STEREO)) { + av_log(s, AV_LOG_ERROR, "unsupported features 0x%02x\n", + features & ~(TMV_PADDING | TMV_STEREO)); + return -1; + } + + ast->codec->codec_type = AVMEDIA_TYPE_AUDIO; + ast->codec->codec_id = AV_CODEC_ID_PCM_U8; + if (features & TMV_STEREO) { + ast->codec->channels = 2; + ast->codec->channel_layout = AV_CH_LAYOUT_STEREO; + } else { + ast->codec->channels = 1; + ast->codec->channel_layout = AV_CH_LAYOUT_MONO; + } + ast->codec->bits_per_coded_sample = 8; + ast->codec->bit_rate = ast->codec->sample_rate * + ast->codec->bits_per_coded_sample; + avpriv_set_pts_info(ast, 32, 1, ast->codec->sample_rate); + + fps.num = ast->codec->sample_rate * ast->codec->channels; + fps.den = tmv->audio_chunk_size; + av_reduce(&fps.num, &fps.den, fps.num, fps.den, 0xFFFFFFFFLL); + + vst->codec->codec_type = AVMEDIA_TYPE_VIDEO; + vst->codec->codec_id = AV_CODEC_ID_TMV; + vst->codec->pix_fmt = AV_PIX_FMT_PAL8; + vst->codec->width = char_cols * 8; + vst->codec->height = char_rows * 8; + avpriv_set_pts_info(vst, 32, fps.den, fps.num); + + if (features & TMV_PADDING) + tmv->padding = + ((tmv->video_chunk_size + tmv->audio_chunk_size + 511) & ~511) - + (tmv->video_chunk_size + tmv->audio_chunk_size); + + vst->codec->bit_rate = ((tmv->video_chunk_size + tmv->padding) * + fps.num * 8) / fps.den; + + return 0; +} + +static int tmv_read_packet(AVFormatContext *s, AVPacket *pkt) +{ + TMVContext *tmv = s->priv_data; + AVIOContext *pb = s->pb; + int ret, pkt_size = tmv->stream_index ? + tmv->audio_chunk_size : tmv->video_chunk_size; + + if (url_feof(pb)) + return AVERROR_EOF; + + ret = av_get_packet(pb, pkt, pkt_size); + + if (tmv->stream_index) + avio_skip(pb, tmv->padding); + + pkt->stream_index = tmv->stream_index; + tmv->stream_index ^= 1; + pkt->flags |= AV_PKT_FLAG_KEY; + + return ret; +} + +static int tmv_read_seek(AVFormatContext *s, int stream_index, + int64_t timestamp, int flags) +{ + TMVContext *tmv = s->priv_data; + int64_t pos; + + if (stream_index) + return -1; + + pos = timestamp * + (tmv->audio_chunk_size + tmv->video_chunk_size + tmv->padding); + + if (avio_seek(s->pb, pos + TMV_HEADER_SIZE, SEEK_SET) < 0) + return -1; + tmv->stream_index = 0; + return 0; +} + +AVInputFormat ff_tmv_demuxer = { + .name = "tmv", + .long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"), + .priv_data_size = sizeof(TMVContext), + .read_probe = tmv_probe, + .read_header = tmv_read_header, + .read_packet = tmv_read_packet, + .read_seek = tmv_read_seek, + .flags = AVFMT_GENERIC_INDEX, +}; |