/* * 8088flex TMV file demuxer * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu> * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; 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/intreadwrite.h" #include "avformat.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, AVFormatParameters *ap) { 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 = CODEC_ID_PCM_U8; ast->codec->channels = features & TMV_STEREO ? 2 : 1; ast->codec->bits_per_coded_sample = 8; ast->codec->bit_rate = ast->codec->sample_rate * ast->codec->bits_per_coded_sample; av_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 = CODEC_ID_TMV; vst->codec->pix_fmt = PIX_FMT_PAL8; vst->codec->width = char_cols * 8; vst->codec->height = char_rows * 8; av_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 (pb->eof_reached) 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); avio_seek(s->pb, pos + TMV_HEADER_SIZE, SEEK_SET); 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, };