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192 lines
5.6 KiB
192 lines
5.6 KiB
/* |
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* 8088flex TMV file demuxer |
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* Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu> |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/** |
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* @file |
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* 8088flex TMV file demuxer |
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* @author Daniel Verkamp |
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* @see http://www.oldskool.org/pc/8088_Corruption |
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*/ |
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#include "libavutil/intreadwrite.h" |
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#include "avformat.h" |
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#include "internal.h" |
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enum { |
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TMV_PADDING = 0x01, |
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TMV_STEREO = 0x02, |
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}; |
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#define TMV_TAG MKTAG('T', 'M', 'A', 'V') |
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typedef struct TMVContext { |
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unsigned audio_chunk_size; |
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unsigned video_chunk_size; |
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unsigned padding; |
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unsigned stream_index; |
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} TMVContext; |
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#define TMV_HEADER_SIZE 12 |
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#define PROBE_MIN_SAMPLE_RATE 5000 |
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#define PROBE_MAX_FPS 120 |
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#define PROBE_MIN_AUDIO_SIZE (PROBE_MIN_SAMPLE_RATE / PROBE_MAX_FPS) |
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static int tmv_probe(AVProbeData *p) |
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{ |
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if (AV_RL32(p->buf) == TMV_TAG && |
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AV_RL16(p->buf+4) >= PROBE_MIN_SAMPLE_RATE && |
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AV_RL16(p->buf+6) >= PROBE_MIN_AUDIO_SIZE && |
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!p->buf[8] && // compression method |
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p->buf[9] && // char cols |
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p->buf[10]) // char rows |
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return AVPROBE_SCORE_MAX / |
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((p->buf[9] == 40 && p->buf[10] == 25) ? 1 : 4); |
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return 0; |
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} |
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static int tmv_read_header(AVFormatContext *s) |
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{ |
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TMVContext *tmv = s->priv_data; |
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AVIOContext *pb = s->pb; |
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AVStream *vst, *ast; |
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AVRational fps; |
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unsigned comp_method, char_cols, char_rows, features; |
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if (avio_rl32(pb) != TMV_TAG) |
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return -1; |
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if (!(vst = avformat_new_stream(s, NULL))) |
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return AVERROR(ENOMEM); |
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if (!(ast = avformat_new_stream(s, NULL))) |
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return AVERROR(ENOMEM); |
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ast->codec->sample_rate = avio_rl16(pb); |
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if (!ast->codec->sample_rate) { |
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av_log(s, AV_LOG_ERROR, "invalid sample rate\n"); |
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return -1; |
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} |
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tmv->audio_chunk_size = avio_rl16(pb); |
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if (!tmv->audio_chunk_size) { |
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av_log(s, AV_LOG_ERROR, "invalid audio chunk size\n"); |
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return -1; |
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} |
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comp_method = avio_r8(pb); |
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if (comp_method) { |
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av_log(s, AV_LOG_ERROR, "unsupported compression method %d\n", |
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comp_method); |
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return -1; |
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} |
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char_cols = avio_r8(pb); |
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char_rows = avio_r8(pb); |
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tmv->video_chunk_size = char_cols * char_rows * 2; |
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features = avio_r8(pb); |
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if (features & ~(TMV_PADDING | TMV_STEREO)) { |
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av_log(s, AV_LOG_ERROR, "unsupported features 0x%02x\n", |
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features & ~(TMV_PADDING | TMV_STEREO)); |
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return -1; |
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} |
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ast->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
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ast->codec->codec_id = AV_CODEC_ID_PCM_U8; |
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ast->codec->channels = features & TMV_STEREO ? 2 : 1; |
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ast->codec->bits_per_coded_sample = 8; |
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ast->codec->bit_rate = ast->codec->sample_rate * |
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ast->codec->bits_per_coded_sample; |
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avpriv_set_pts_info(ast, 32, 1, ast->codec->sample_rate); |
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fps.num = ast->codec->sample_rate * ast->codec->channels; |
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fps.den = tmv->audio_chunk_size; |
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av_reduce(&fps.num, &fps.den, fps.num, fps.den, 0xFFFFFFFFLL); |
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vst->codec->codec_type = AVMEDIA_TYPE_VIDEO; |
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vst->codec->codec_id = AV_CODEC_ID_TMV; |
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vst->codec->pix_fmt = PIX_FMT_PAL8; |
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vst->codec->width = char_cols * 8; |
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vst->codec->height = char_rows * 8; |
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avpriv_set_pts_info(vst, 32, fps.den, fps.num); |
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if (features & TMV_PADDING) |
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tmv->padding = |
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((tmv->video_chunk_size + tmv->audio_chunk_size + 511) & ~511) - |
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(tmv->video_chunk_size + tmv->audio_chunk_size); |
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vst->codec->bit_rate = ((tmv->video_chunk_size + tmv->padding) * |
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fps.num * 8) / fps.den; |
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return 0; |
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} |
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static int tmv_read_packet(AVFormatContext *s, AVPacket *pkt) |
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{ |
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TMVContext *tmv = s->priv_data; |
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AVIOContext *pb = s->pb; |
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int ret, pkt_size = tmv->stream_index ? |
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tmv->audio_chunk_size : tmv->video_chunk_size; |
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if (url_feof(pb)) |
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return AVERROR_EOF; |
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ret = av_get_packet(pb, pkt, pkt_size); |
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if (tmv->stream_index) |
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avio_skip(pb, tmv->padding); |
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pkt->stream_index = tmv->stream_index; |
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tmv->stream_index ^= 1; |
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pkt->flags |= AV_PKT_FLAG_KEY; |
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return ret; |
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} |
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static int tmv_read_seek(AVFormatContext *s, int stream_index, |
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int64_t timestamp, int flags) |
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{ |
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TMVContext *tmv = s->priv_data; |
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int64_t pos; |
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if (stream_index) |
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return -1; |
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pos = timestamp * |
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(tmv->audio_chunk_size + tmv->video_chunk_size + tmv->padding); |
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if (avio_seek(s->pb, pos + TMV_HEADER_SIZE, SEEK_SET) < 0) |
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return -1; |
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tmv->stream_index = 0; |
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return 0; |
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} |
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AVInputFormat ff_tmv_demuxer = { |
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.name = "tmv", |
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.long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"), |
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.priv_data_size = sizeof(TMVContext), |
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.read_probe = tmv_probe, |
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.read_header = tmv_read_header, |
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.read_packet = tmv_read_packet, |
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.read_seek = tmv_read_seek, |
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.flags = AVFMT_GENERIC_INDEX, |
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};
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