yading@11: /* yading@11: * General DV muxer/demuxer yading@11: * Copyright (c) 2003 Roman Shaposhnik yading@11: * yading@11: * Many thanks to Dan Dennedy for providing wealth yading@11: * of DV technical info. yading@11: * yading@11: * Raw DV format yading@11: * Copyright (c) 2002 Fabrice Bellard yading@11: * yading@11: * 50 Mbps (DVCPRO50) and 100 Mbps (DVCPRO HD) support yading@11: * Copyright (c) 2006 Daniel Maas yading@11: * Funded by BBC Research & Development yading@11: * yading@11: * This file is part of FFmpeg. yading@11: * yading@11: * FFmpeg is free software; you can redistribute it and/or yading@11: * modify it under the terms of the GNU Lesser General Public yading@11: * License as published by the Free Software Foundation; either yading@11: * version 2.1 of the License, or (at your option) any later version. yading@11: * yading@11: * FFmpeg is distributed in the hope that it will be useful, yading@11: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@11: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@11: * Lesser General Public License for more details. yading@11: * yading@11: * You should have received a copy of the GNU Lesser General Public yading@11: * License along with FFmpeg; if not, write to the Free Software yading@11: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@11: */ yading@11: #include yading@11: #include "avformat.h" yading@11: #include "internal.h" yading@11: #include "libavcodec/dv_profile.h" yading@11: #include "libavcodec/dvdata.h" yading@11: #include "libavutil/channel_layout.h" yading@11: #include "libavutil/intreadwrite.h" yading@11: #include "libavutil/mathematics.h" yading@11: #include "libavutil/timecode.h" yading@11: #include "dv.h" yading@11: #include "libavutil/avassert.h" yading@11: yading@11: struct DVDemuxContext { yading@11: const DVprofile* sys; /* Current DV profile. E.g.: 525/60, 625/50 */ yading@11: AVFormatContext* fctx; yading@11: AVStream* vst; yading@11: AVStream* ast[4]; yading@11: AVPacket audio_pkt[4]; yading@11: uint8_t audio_buf[4][8192]; yading@11: int ach; yading@11: int frames; yading@11: uint64_t abytes; yading@11: }; yading@11: yading@11: static inline uint16_t dv_audio_12to16(uint16_t sample) yading@11: { yading@11: uint16_t shift, result; yading@11: yading@11: sample = (sample < 0x800) ? sample : sample | 0xf000; yading@11: shift = (sample & 0xf00) >> 8; yading@11: yading@11: if (shift < 0x2 || shift > 0xd) { yading@11: result = sample; yading@11: } else if (shift < 0x8) { yading@11: shift--; yading@11: result = (sample - (256 * shift)) << shift; yading@11: } else { yading@11: shift = 0xe - shift; yading@11: result = ((sample + ((256 * shift) + 1)) << shift) - 1; yading@11: } yading@11: yading@11: return result; yading@11: } yading@11: yading@11: /* yading@11: * This is the dumbest implementation of all -- it simply looks at yading@11: * a fixed offset and if pack isn't there -- fails. We might want yading@11: * to have a fallback mechanism for complete search of missing packs. yading@11: */ yading@11: static const uint8_t* dv_extract_pack(uint8_t* frame, enum dv_pack_type t) yading@11: { yading@11: int offs; yading@11: yading@11: switch (t) { yading@11: case dv_audio_source: yading@11: offs = (80*6 + 80*16*3 + 3); yading@11: break; yading@11: case dv_audio_control: yading@11: offs = (80*6 + 80*16*4 + 3); yading@11: break; yading@11: case dv_video_control: yading@11: offs = (80*5 + 48 + 5); yading@11: break; yading@11: case dv_timecode: yading@11: offs = (80*1 + 3 + 3); yading@11: break; yading@11: default: yading@11: return NULL; yading@11: } yading@11: yading@11: return frame[offs] == t ? &frame[offs] : NULL; yading@11: } yading@11: yading@11: static const int dv_audio_frequency[3] = { yading@11: 48000, 44100, 32000, yading@11: }; yading@11: yading@11: /* yading@11: * There's a couple of assumptions being made here: yading@11: * 1. By default we silence erroneous (0x8000/16bit 0x800/12bit) audio samples. yading@11: * We can pass them upwards when libavcodec will be ready to deal with them. yading@11: * 2. We don't do software emphasis. yading@11: * 3. Audio is always returned as 16bit linear samples: 12bit nonlinear samples yading@11: * are converted into 16bit linear ones. yading@11: */ yading@11: static int dv_extract_audio(uint8_t* frame, uint8_t* ppcm[4], yading@11: const DVprofile *sys) yading@11: { yading@11: int size, chan, i, j, d, of, smpls, freq, quant, half_ch; yading@11: uint16_t lc, rc; yading@11: const uint8_t* as_pack; yading@11: uint8_t *pcm, ipcm; yading@11: yading@11: as_pack = dv_extract_pack(frame, dv_audio_source); yading@11: if (!as_pack) /* No audio ? */ yading@11: return 0; yading@11: yading@11: smpls = as_pack[1] & 0x3f; /* samples in this frame - min. samples */ yading@11: freq = (as_pack[4] >> 3) & 0x07; /* 0 - 48kHz, 1 - 44,1kHz, 2 - 32kHz */ yading@11: quant = as_pack[4] & 0x07; /* 0 - 16bit linear, 1 - 12bit nonlinear */ yading@11: yading@11: if (quant > 1) yading@11: return -1; /* unsupported quantization */ yading@11: yading@11: if (freq >= FF_ARRAY_ELEMS(dv_audio_frequency)) yading@11: return AVERROR_INVALIDDATA; yading@11: yading@11: size = (sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */ yading@11: half_ch = sys->difseg_size / 2; yading@11: yading@11: /* We work with 720p frames split in half, thus even frames have yading@11: * channels 0,1 and odd 2,3. */ yading@11: ipcm = (sys->height == 720 && !(frame[1] & 0x0C)) ? 2 : 0; yading@11: yading@11: if (ipcm + sys->n_difchan > (quant == 1 ? 2 : 4)) { yading@11: av_log(NULL, AV_LOG_ERROR, "too many dv pcm frames\n"); yading@11: return AVERROR_INVALIDDATA; yading@11: } yading@11: yading@11: /* for each DIF channel */ yading@11: for (chan = 0; chan < sys->n_difchan; chan++) { yading@11: av_assert0(ipcm<4); yading@11: pcm = ppcm[ipcm++]; yading@11: if (!pcm) yading@11: break; yading@11: yading@11: /* for each DIF segment */ yading@11: for (i = 0; i < sys->difseg_size; i++) { yading@11: frame += 6 * 80; /* skip DIF segment header */ yading@11: if (quant == 1 && i == half_ch) { yading@11: /* next stereo channel (12bit mode only) */ yading@11: av_assert0(ipcm<4); yading@11: pcm = ppcm[ipcm++]; yading@11: if (!pcm) yading@11: break; yading@11: } yading@11: yading@11: /* for each AV sequence */ yading@11: for (j = 0; j < 9; j++) { yading@11: for (d = 8; d < 80; d += 2) { yading@11: if (quant == 0) { /* 16bit quantization */ yading@11: of = sys->audio_shuffle[i][j] + (d - 8) / 2 * sys->audio_stride; yading@11: if (of*2 >= size) yading@11: continue; yading@11: yading@11: pcm[of*2] = frame[d+1]; // FIXME: maybe we have to admit yading@11: pcm[of*2+1] = frame[d]; // that DV is a big-endian PCM yading@11: if (pcm[of*2+1] == 0x80 && pcm[of*2] == 0x00) yading@11: pcm[of*2+1] = 0; yading@11: } else { /* 12bit quantization */ yading@11: lc = ((uint16_t)frame[d] << 4) | yading@11: ((uint16_t)frame[d+2] >> 4); yading@11: rc = ((uint16_t)frame[d+1] << 4) | yading@11: ((uint16_t)frame[d+2] & 0x0f); yading@11: lc = (lc == 0x800 ? 0 : dv_audio_12to16(lc)); yading@11: rc = (rc == 0x800 ? 0 : dv_audio_12to16(rc)); yading@11: yading@11: of = sys->audio_shuffle[i%half_ch][j] + (d - 8) / 3 * sys->audio_stride; yading@11: if (of*2 >= size) yading@11: continue; yading@11: yading@11: pcm[of*2] = lc & 0xff; // FIXME: maybe we have to admit yading@11: pcm[of*2+1] = lc >> 8; // that DV is a big-endian PCM yading@11: of = sys->audio_shuffle[i%half_ch+half_ch][j] + yading@11: (d - 8) / 3 * sys->audio_stride; yading@11: pcm[of*2] = rc & 0xff; // FIXME: maybe we have to admit yading@11: pcm[of*2+1] = rc >> 8; // that DV is a big-endian PCM yading@11: ++d; yading@11: } yading@11: } yading@11: yading@11: frame += 16 * 80; /* 15 Video DIFs + 1 Audio DIF */ yading@11: } yading@11: } yading@11: } yading@11: yading@11: return size; yading@11: } yading@11: yading@11: static int dv_extract_audio_info(DVDemuxContext* c, uint8_t* frame) yading@11: { yading@11: const uint8_t* as_pack; yading@11: int freq, stype, smpls, quant, i, ach; yading@11: yading@11: as_pack = dv_extract_pack(frame, dv_audio_source); yading@11: if (!as_pack || !c->sys) { /* No audio ? */ yading@11: c->ach = 0; yading@11: return 0; yading@11: } yading@11: yading@11: smpls = as_pack[1] & 0x3f; /* samples in this frame - min. samples */ yading@11: freq = (as_pack[4] >> 3) & 0x07; /* 0 - 48kHz, 1 - 44,1kHz, 2 - 32kHz */ yading@11: stype = (as_pack[3] & 0x1f); /* 0 - 2CH, 2 - 4CH, 3 - 8CH */ yading@11: quant = as_pack[4] & 0x07; /* 0 - 16bit linear, 1 - 12bit nonlinear */ yading@11: yading@11: if (freq >= FF_ARRAY_ELEMS(dv_audio_frequency)) { yading@11: av_log(c->fctx, AV_LOG_ERROR, yading@11: "Unrecognized audio sample rate index (%d)\n", freq); yading@11: return 0; yading@11: } yading@11: yading@11: if (stype > 3) { yading@11: av_log(c->fctx, AV_LOG_ERROR, "stype %d is invalid\n", stype); yading@11: c->ach = 0; yading@11: return 0; yading@11: } yading@11: yading@11: /* note: ach counts PAIRS of channels (i.e. stereo channels) */ yading@11: ach = ((int[4]){ 1, 0, 2, 4})[stype]; yading@11: if (ach == 1 && quant && freq == 2) yading@11: ach = 2; yading@11: yading@11: /* Dynamic handling of the audio streams in DV */ yading@11: for (i = 0; i < ach; i++) { yading@11: if (!c->ast[i]) { yading@11: c->ast[i] = avformat_new_stream(c->fctx, NULL); yading@11: if (!c->ast[i]) yading@11: break; yading@11: avpriv_set_pts_info(c->ast[i], 64, 1, 30000); yading@11: c->ast[i]->codec->codec_type = AVMEDIA_TYPE_AUDIO; yading@11: c->ast[i]->codec->codec_id = AV_CODEC_ID_PCM_S16LE; yading@11: yading@11: av_init_packet(&c->audio_pkt[i]); yading@11: c->audio_pkt[i].size = 0; yading@11: c->audio_pkt[i].data = c->audio_buf[i]; yading@11: c->audio_pkt[i].stream_index = c->ast[i]->index; yading@11: c->audio_pkt[i].flags |= AV_PKT_FLAG_KEY; yading@11: } yading@11: c->ast[i]->codec->sample_rate = dv_audio_frequency[freq]; yading@11: c->ast[i]->codec->channels = 2; yading@11: c->ast[i]->codec->channel_layout = AV_CH_LAYOUT_STEREO; yading@11: c->ast[i]->codec->bit_rate = 2 * dv_audio_frequency[freq] * 16; yading@11: c->ast[i]->start_time = 0; yading@11: } yading@11: c->ach = i; yading@11: yading@11: return (c->sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */; yading@11: } yading@11: yading@11: static int dv_extract_video_info(DVDemuxContext *c, uint8_t* frame) yading@11: { yading@11: const uint8_t* vsc_pack; yading@11: AVCodecContext* avctx; yading@11: int apt, is16_9; yading@11: int size = 0; yading@11: yading@11: if (c->sys) { yading@11: avctx = c->vst->codec; yading@11: yading@11: avpriv_set_pts_info(c->vst, 64, c->sys->time_base.num, yading@11: c->sys->time_base.den); yading@11: avctx->time_base= c->sys->time_base; yading@11: yading@11: /* finding out SAR is a little bit messy */ yading@11: vsc_pack = dv_extract_pack(frame, dv_video_control); yading@11: apt = frame[4] & 0x07; yading@11: is16_9 = (vsc_pack && ((vsc_pack[2] & 0x07) == 0x02 || yading@11: (!apt && (vsc_pack[2] & 0x07) == 0x07))); yading@11: c->vst->sample_aspect_ratio = c->sys->sar[is16_9]; yading@11: avctx->bit_rate = av_rescale_q(c->sys->frame_size, (AVRational){8,1}, yading@11: c->sys->time_base); yading@11: size = c->sys->frame_size; yading@11: } yading@11: return size; yading@11: } yading@11: yading@11: static int dv_extract_timecode(DVDemuxContext* c, uint8_t* frame, char *tc) yading@11: { yading@11: const uint8_t *tc_pack; yading@11: yading@11: // For PAL systems, drop frame bit is replaced by an arbitrary yading@11: // bit so its value should not be considered. Drop frame timecode yading@11: // is only relevant for NTSC systems. yading@11: int prevent_df = c->sys->ltc_divisor == 25 || c->sys->ltc_divisor == 50; yading@11: yading@11: tc_pack = dv_extract_pack(frame, dv_timecode); yading@11: if (!tc_pack) yading@11: return 0; yading@11: av_timecode_make_smpte_tc_string(tc, AV_RB32(tc_pack + 1), prevent_df); yading@11: return 1; yading@11: } yading@11: yading@11: /* yading@11: * The following 3 functions constitute our interface to the world yading@11: */ yading@11: yading@11: DVDemuxContext* avpriv_dv_init_demux(AVFormatContext *s) yading@11: { yading@11: DVDemuxContext *c; yading@11: yading@11: c = av_mallocz(sizeof(DVDemuxContext)); yading@11: if (!c) yading@11: return NULL; yading@11: yading@11: c->vst = avformat_new_stream(s, NULL); yading@11: if (!c->vst) { yading@11: av_free(c); yading@11: return NULL; yading@11: } yading@11: yading@11: c->fctx = s; yading@11: c->vst->codec->codec_type = AVMEDIA_TYPE_VIDEO; yading@11: c->vst->codec->codec_id = AV_CODEC_ID_DVVIDEO; yading@11: c->vst->codec->bit_rate = 25000000; yading@11: c->vst->start_time = 0; yading@11: yading@11: return c; yading@11: } yading@11: yading@11: int avpriv_dv_get_packet(DVDemuxContext *c, AVPacket *pkt) yading@11: { yading@11: int size = -1; yading@11: int i; yading@11: yading@11: for (i = 0; i < c->ach; i++) { yading@11: if (c->ast[i] && c->audio_pkt[i].size) { yading@11: *pkt = c->audio_pkt[i]; yading@11: c->audio_pkt[i].size = 0; yading@11: size = pkt->size; yading@11: break; yading@11: } yading@11: } yading@11: yading@11: return size; yading@11: } yading@11: yading@11: int avpriv_dv_produce_packet(DVDemuxContext *c, AVPacket *pkt, yading@11: uint8_t* buf, int buf_size, int64_t pos) yading@11: { yading@11: int size, i; yading@11: uint8_t *ppcm[4] = {0}; yading@11: yading@11: if (buf_size < DV_PROFILE_BYTES || yading@11: !(c->sys = avpriv_dv_frame_profile(c->sys, buf, buf_size)) || yading@11: buf_size < c->sys->frame_size) { yading@11: return -1; /* Broken frame, or not enough data */ yading@11: } yading@11: yading@11: /* Queueing audio packet */ yading@11: /* FIXME: in case of no audio/bad audio we have to do something */ yading@11: size = dv_extract_audio_info(c, buf); yading@11: for (i = 0; i < c->ach; i++) { yading@11: c->audio_pkt[i].pos = pos; yading@11: c->audio_pkt[i].size = size; yading@11: c->audio_pkt[i].pts = c->abytes * 30000 * 8 / c->ast[i]->codec->bit_rate; yading@11: ppcm[i] = c->audio_buf[i]; yading@11: } yading@11: if (c->ach) yading@11: dv_extract_audio(buf, ppcm, c->sys); yading@11: yading@11: /* We work with 720p frames split in half, thus even frames have yading@11: * channels 0,1 and odd 2,3. */ yading@11: if (c->sys->height == 720) { yading@11: if (buf[1] & 0x0C) { yading@11: c->audio_pkt[2].size = c->audio_pkt[3].size = 0; yading@11: } else { yading@11: c->audio_pkt[0].size = c->audio_pkt[1].size = 0; yading@11: c->abytes += size; yading@11: } yading@11: } else { yading@11: c->abytes += size; yading@11: } yading@11: yading@11: /* Now it's time to return video packet */ yading@11: size = dv_extract_video_info(c, buf); yading@11: av_init_packet(pkt); yading@11: pkt->data = buf; yading@11: pkt->pos = pos; yading@11: pkt->size = size; yading@11: pkt->flags |= AV_PKT_FLAG_KEY; yading@11: pkt->stream_index = c->vst->index; yading@11: pkt->pts = c->frames; yading@11: yading@11: c->frames++; yading@11: yading@11: return size; yading@11: } yading@11: yading@11: static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c, yading@11: int64_t timestamp, int flags) yading@11: { yading@11: // FIXME: sys may be wrong if last dv_read_packet() failed (buffer is junk) yading@11: const DVprofile* sys = avpriv_dv_codec_profile(c->vst->codec); yading@11: int64_t offset; yading@11: int64_t size = avio_size(s->pb) - s->data_offset; yading@11: int64_t max_offset = ((size-1) / sys->frame_size) * sys->frame_size; yading@11: yading@11: offset = sys->frame_size * timestamp; yading@11: yading@11: if (size >= 0 && offset > max_offset) offset = max_offset; yading@11: else if (offset < 0) offset = 0; yading@11: yading@11: return offset + s->data_offset; yading@11: } yading@11: yading@11: void ff_dv_offset_reset(DVDemuxContext *c, int64_t frame_offset) yading@11: { yading@11: c->frames= frame_offset; yading@11: if (c->ach) { yading@11: if (c->sys) { yading@11: c->abytes= av_rescale_q(c->frames, c->sys->time_base, yading@11: (AVRational){8, c->ast[0]->codec->bit_rate}); yading@11: }else yading@11: av_log(c->fctx, AV_LOG_ERROR, "cannot adjust audio bytes\n"); yading@11: } yading@11: c->audio_pkt[0].size = c->audio_pkt[1].size = 0; yading@11: c->audio_pkt[2].size = c->audio_pkt[3].size = 0; yading@11: } yading@11: yading@11: /************************************************************ yading@11: * Implementation of the easiest DV storage of all -- raw DV. yading@11: ************************************************************/ yading@11: yading@11: typedef struct RawDVContext { yading@11: DVDemuxContext* dv_demux; yading@11: uint8_t buf[DV_MAX_FRAME_SIZE]; yading@11: } RawDVContext; yading@11: yading@11: static int dv_read_timecode(AVFormatContext *s) { yading@11: int ret; yading@11: char timecode[AV_TIMECODE_STR_SIZE]; yading@11: int64_t pos = avio_tell(s->pb); yading@11: yading@11: // Read 3 DIF blocks: Header block and 2 Subcode blocks. yading@11: int partial_frame_size = 3 * 80; yading@11: uint8_t *partial_frame = av_mallocz(sizeof(*partial_frame) * yading@11: partial_frame_size); yading@11: yading@11: RawDVContext *c = s->priv_data; yading@11: ret = avio_read(s->pb, partial_frame, partial_frame_size); yading@11: if (ret < 0) yading@11: goto finish; yading@11: yading@11: if (ret < partial_frame_size) { yading@11: ret = -1; yading@11: goto finish; yading@11: } yading@11: yading@11: ret = dv_extract_timecode(c->dv_demux, partial_frame, timecode); yading@11: if (ret) yading@11: av_dict_set(&s->metadata, "timecode", timecode, 0); yading@11: else yading@11: av_log(s, AV_LOG_ERROR, "Detected timecode is invalid\n"); yading@11: yading@11: finish: yading@11: av_free(partial_frame); yading@11: avio_seek(s->pb, pos, SEEK_SET); yading@11: return ret; yading@11: } yading@11: yading@11: static int dv_read_header(AVFormatContext *s) yading@11: { yading@11: unsigned state, marker_pos = 0; yading@11: RawDVContext *c = s->priv_data; yading@11: yading@11: c->dv_demux = avpriv_dv_init_demux(s); yading@11: if (!c->dv_demux) yading@11: return -1; yading@11: yading@11: state = avio_rb32(s->pb); yading@11: while ((state & 0xffffff7f) != 0x1f07003f) { yading@11: if (url_feof(s->pb)) { yading@11: av_log(s, AV_LOG_ERROR, "Cannot find DV header.\n"); yading@11: return -1; yading@11: } yading@11: if (state == 0x003f0700 || state == 0xff3f0700) yading@11: marker_pos = avio_tell(s->pb); yading@11: if (state == 0xff3f0701 && avio_tell(s->pb) - marker_pos == 80) { yading@11: avio_seek(s->pb, -163, SEEK_CUR); yading@11: state = avio_rb32(s->pb); yading@11: break; yading@11: } yading@11: state = (state << 8) | avio_r8(s->pb); yading@11: } yading@11: AV_WB32(c->buf, state); yading@11: yading@11: if (avio_read(s->pb, c->buf + 4, DV_PROFILE_BYTES - 4) != DV_PROFILE_BYTES - 4 || yading@11: avio_seek(s->pb, -DV_PROFILE_BYTES, SEEK_CUR) < 0) yading@11: return AVERROR(EIO); yading@11: yading@11: c->dv_demux->sys = avpriv_dv_frame_profile(c->dv_demux->sys, c->buf, DV_PROFILE_BYTES); yading@11: if (!c->dv_demux->sys) { yading@11: av_log(s, AV_LOG_ERROR, "Can't determine profile of DV input stream.\n"); yading@11: return -1; yading@11: } yading@11: yading@11: s->bit_rate = av_rescale_q(c->dv_demux->sys->frame_size, (AVRational){8,1}, yading@11: c->dv_demux->sys->time_base); yading@11: yading@11: if (s->pb->seekable) yading@11: dv_read_timecode(s); yading@11: yading@11: return 0; yading@11: } yading@11: yading@11: yading@11: static int dv_read_packet(AVFormatContext *s, AVPacket *pkt) yading@11: { yading@11: int size; yading@11: RawDVContext *c = s->priv_data; yading@11: yading@11: size = avpriv_dv_get_packet(c->dv_demux, pkt); yading@11: yading@11: if (size < 0) { yading@11: int64_t pos = avio_tell(s->pb); yading@11: if (!c->dv_demux->sys) yading@11: return AVERROR(EIO); yading@11: size = c->dv_demux->sys->frame_size; yading@11: if (avio_read(s->pb, c->buf, size) <= 0) yading@11: return AVERROR(EIO); yading@11: yading@11: size = avpriv_dv_produce_packet(c->dv_demux, pkt, c->buf, size, pos); yading@11: } yading@11: yading@11: return size; yading@11: } yading@11: yading@11: static int dv_read_seek(AVFormatContext *s, int stream_index, yading@11: int64_t timestamp, int flags) yading@11: { yading@11: RawDVContext *r = s->priv_data; yading@11: DVDemuxContext *c = r->dv_demux; yading@11: int64_t offset = dv_frame_offset(s, c, timestamp, flags); yading@11: yading@11: if (avio_seek(s->pb, offset, SEEK_SET) < 0) yading@11: return -1; yading@11: yading@11: ff_dv_offset_reset(c, offset / c->sys->frame_size); yading@11: return 0; yading@11: } yading@11: yading@11: static int dv_read_close(AVFormatContext *s) yading@11: { yading@11: RawDVContext *c = s->priv_data; yading@11: av_free(c->dv_demux); yading@11: return 0; yading@11: } yading@11: yading@11: static int dv_probe(AVProbeData *p) yading@11: { yading@11: unsigned state, marker_pos = 0; yading@11: int i; yading@11: int matches = 0; yading@11: int secondary_matches = 0; yading@11: yading@11: if (p->buf_size < 5) yading@11: return 0; yading@11: yading@11: state = AV_RB32(p->buf); yading@11: for (i = 4; i < p->buf_size; i++) { yading@11: if ((state & 0xffffff7f) == 0x1f07003f) yading@11: matches++; yading@11: // any section header, also with seq/chan num != 0, yading@11: // should appear around every 12000 bytes, at least 10 per frame yading@11: if ((state & 0xff07ff7f) == 0x1f07003f) yading@11: secondary_matches++; yading@11: if (state == 0x003f0700 || state == 0xff3f0700) yading@11: marker_pos = i; yading@11: if (state == 0xff3f0701 && i - marker_pos == 80) yading@11: matches++; yading@11: state = (state << 8) | p->buf[i]; yading@11: } yading@11: yading@11: if (matches && p->buf_size / matches < 1024*1024) { yading@11: if (matches > 4 || (secondary_matches >= 10 && p->buf_size / secondary_matches < 24000)) yading@11: return AVPROBE_SCORE_MAX*3/4; // not max to avoid dv in mov to match yading@11: return AVPROBE_SCORE_MAX/4; yading@11: } yading@11: return 0; yading@11: } yading@11: yading@11: #if CONFIG_DV_DEMUXER yading@11: AVInputFormat ff_dv_demuxer = { yading@11: .name = "dv", yading@11: .long_name = NULL_IF_CONFIG_SMALL("DV (Digital Video)"), yading@11: .priv_data_size = sizeof(RawDVContext), yading@11: .read_probe = dv_probe, yading@11: .read_header = dv_read_header, yading@11: .read_packet = dv_read_packet, yading@11: .read_close = dv_read_close, yading@11: .read_seek = dv_read_seek, yading@11: .extensions = "dv,dif", yading@11: }; yading@11: #endif