/* * MPEG-1/2 muxer * Copyright (c) 2000, 2001, 2002 Fabrice Bellard * * 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 */ #include #include "libavutil/attributes.h" #include "libavutil/fifo.h" #include "libavutil/log.h" #include "libavutil/mathematics.h" #include "libavutil/opt.h" #include "libavcodec/put_bits.h" #include "avformat.h" #include "internal.h" #include "mpeg.h" #define MAX_PAYLOAD_SIZE 4096 #undef NDEBUG #include typedef struct PacketDesc { int64_t pts; int64_t dts; int size; int unwritten_size; struct PacketDesc *next; } PacketDesc; typedef struct StreamInfo { AVFifoBuffer *fifo; uint8_t id; int max_buffer_size; /* in bytes */ int buffer_index; PacketDesc *predecode_packet; PacketDesc *premux_packet; PacketDesc **next_packet; int packet_number; uint8_t lpcm_header[3]; int lpcm_align; int bytes_to_iframe; int align_iframe; int64_t vobu_start_pts; } StreamInfo; typedef struct MpegMuxContext { const AVClass *class; int packet_size; /* required packet size */ int packet_number; int pack_header_freq; /* frequency (in packets^-1) at which we send pack headers */ int system_header_freq; int system_header_size; int mux_rate; /* bitrate in units of 50 bytes/s */ /* stream info */ int audio_bound; int video_bound; int is_mpeg2; int is_vcd; int is_svcd; int is_dvd; int64_t last_scr; /* current system clock */ double vcd_padding_bitrate; // FIXME floats int64_t vcd_padding_bytes_written; int preload; } MpegMuxContext; extern AVOutputFormat ff_mpeg1vcd_muxer; extern AVOutputFormat ff_mpeg2dvd_muxer; extern AVOutputFormat ff_mpeg2svcd_muxer; extern AVOutputFormat ff_mpeg2vob_muxer; static int put_pack_header(AVFormatContext *ctx, uint8_t *buf, int64_t timestamp) { MpegMuxContext *s = ctx->priv_data; PutBitContext pb; init_put_bits(&pb, buf, 128); put_bits32(&pb, PACK_START_CODE); if (s->is_mpeg2) put_bits(&pb, 2, 0x1); else put_bits(&pb, 4, 0x2); put_bits(&pb, 3, (uint32_t)((timestamp >> 30) & 0x07)); put_bits(&pb, 1, 1); put_bits(&pb, 15, (uint32_t)((timestamp >> 15) & 0x7fff)); put_bits(&pb, 1, 1); put_bits(&pb, 15, (uint32_t)((timestamp) & 0x7fff)); put_bits(&pb, 1, 1); if (s->is_mpeg2) /* clock extension */ put_bits(&pb, 9, 0); put_bits(&pb, 1, 1); put_bits(&pb, 22, s->mux_rate); put_bits(&pb, 1, 1); if (s->is_mpeg2) { put_bits(&pb, 1, 1); put_bits(&pb, 5, 0x1f); /* reserved */ put_bits(&pb, 3, 0); /* stuffing length */ } flush_put_bits(&pb); return put_bits_ptr(&pb) - pb.buf; } static int put_system_header(AVFormatContext *ctx, uint8_t *buf, int only_for_stream_id) { MpegMuxContext *s = ctx->priv_data; int size, i, private_stream_coded, id; PutBitContext pb; init_put_bits(&pb, buf, 128); put_bits32(&pb, SYSTEM_HEADER_START_CODE); put_bits(&pb, 16, 0); put_bits(&pb, 1, 1); /* maximum bit rate of the multiplexed stream */ put_bits(&pb, 22, s->mux_rate); put_bits(&pb, 1, 1); /* marker */ if (s->is_vcd && only_for_stream_id == VIDEO_ID) { /* This header applies only to the video stream * (see VCD standard p. IV-7) */ put_bits(&pb, 6, 0); } else put_bits(&pb, 6, s->audio_bound); if (s->is_vcd) { /* see VCD standard, p. IV-7 */ put_bits(&pb, 1, 0); put_bits(&pb, 1, 1); } else { put_bits(&pb, 1, 0); /* variable bitrate */ put_bits(&pb, 1, 0); /* nonconstrained bitstream */ } if (s->is_vcd || s->is_dvd) { /* see VCD standard p IV-7 */ put_bits(&pb, 1, 1); /* audio locked */ put_bits(&pb, 1, 1); /* video locked */ } else { put_bits(&pb, 1, 0); /* audio locked */ put_bits(&pb, 1, 0); /* video locked */ } put_bits(&pb, 1, 1); /* marker */ if (s->is_vcd && (only_for_stream_id & 0xe0) == AUDIO_ID) { /* This header applies only to the audio stream * (see VCD standard p. IV-7) */ put_bits(&pb, 5, 0); } else put_bits(&pb, 5, s->video_bound); if (s->is_dvd) { put_bits(&pb, 1, 0); /* packet_rate_restriction_flag */ put_bits(&pb, 7, 0x7f); /* reserved byte */ } else put_bits(&pb, 8, 0xff); /* reserved byte */ /* DVD-Video Stream_bound entries * id (0xB9) video, maximum P-STD for stream 0xE0. (P-STD_buffer_bound_scale = 1) * id (0xB8) audio, maximum P-STD for any MPEG audio (0xC0 to 0xC7) streams. If there are none set to 4096 (32x128). (P-STD_buffer_bound_scale = 0) * id (0xBD) private stream 1 (audio other than MPEG and subpictures). (P-STD_buffer_bound_scale = 1) * id (0xBF) private stream 2, NAV packs, set to 2x1024. */ if (s->is_dvd) { int P_STD_max_video = 0; int P_STD_max_mpeg_audio = 0; int P_STD_max_mpeg_PS1 = 0; for (i = 0; i < ctx->nb_streams; i++) { StreamInfo *stream = ctx->streams[i]->priv_data; id = stream->id; if (id == 0xbd && stream->max_buffer_size > P_STD_max_mpeg_PS1) { P_STD_max_mpeg_PS1 = stream->max_buffer_size; } else if (id >= 0xc0 && id <= 0xc7 && stream->max_buffer_size > P_STD_max_mpeg_audio) { P_STD_max_mpeg_audio = stream->max_buffer_size; } else if (id == 0xe0 && stream->max_buffer_size > P_STD_max_video) { P_STD_max_video = stream->max_buffer_size; } } /* video */ put_bits(&pb, 8, 0xb9); /* stream ID */ put_bits(&pb, 2, 3); put_bits(&pb, 1, 1); put_bits(&pb, 13, P_STD_max_video / 1024); /* audio */ if (P_STD_max_mpeg_audio == 0) P_STD_max_mpeg_audio = 4096; put_bits(&pb, 8, 0xb8); /* stream ID */ put_bits(&pb, 2, 3); put_bits(&pb, 1, 0); put_bits(&pb, 13, P_STD_max_mpeg_audio / 128); /* private stream 1 */ put_bits(&pb, 8, 0xbd); /* stream ID */ put_bits(&pb, 2, 3); put_bits(&pb, 1, 0); put_bits(&pb, 13, P_STD_max_mpeg_PS1 / 128); /* private stream 2 */ put_bits(&pb, 8, 0xbf); /* stream ID */ put_bits(&pb, 2, 3); put_bits(&pb, 1, 1); put_bits(&pb, 13, 2); } else { /* audio stream info */ private_stream_coded = 0; for (i = 0; i < ctx->nb_streams; i++) { StreamInfo *stream = ctx->streams[i]->priv_data; /* For VCDs, only include the stream info for the stream * that the pack which contains this system belongs to. * (see VCD standard p. IV-7) */ if (!s->is_vcd || stream->id == only_for_stream_id || only_for_stream_id == 0) { id = stream->id; if (id < 0xc0) { /* special case for private streams (AC-3 uses that) */ if (private_stream_coded) continue; private_stream_coded = 1; id = 0xbd; } put_bits(&pb, 8, id); /* stream ID */ put_bits(&pb, 2, 3); if (id < 0xe0) { /* audio */ put_bits(&pb, 1, 0); put_bits(&pb, 13, stream->max_buffer_size / 128); } else { /* video */ put_bits(&pb, 1, 1); put_bits(&pb, 13, stream->max_buffer_size / 1024); } } } } flush_put_bits(&pb); size = put_bits_ptr(&pb) - pb.buf; /* patch packet size */ buf[4] = (size - 6) >> 8; buf[5] = (size - 6) & 0xff; return size; } static int get_system_header_size(AVFormatContext *ctx) { int buf_index, i, private_stream_coded; StreamInfo *stream; MpegMuxContext *s = ctx->priv_data; if (s->is_dvd) return 18; // DVD-Video system headers are 18 bytes fixed length. buf_index = 12; private_stream_coded = 0; for (i = 0; i < ctx->nb_streams; i++) { stream = ctx->streams[i]->priv_data; if (stream->id < 0xc0) { if (private_stream_coded) continue; private_stream_coded = 1; } buf_index += 3; } return buf_index; } static av_cold int mpeg_mux_init(AVFormatContext *ctx) { MpegMuxContext *s = ctx->priv_data; int bitrate, i, mpa_id, mpv_id, h264_id, mps_id, ac3_id, dts_id, lpcm_id, j; AVStream *st; StreamInfo *stream; int audio_bitrate; int video_bitrate; s->packet_number = 0; s->is_vcd = (CONFIG_MPEG1VCD_MUXER && ctx->oformat == &ff_mpeg1vcd_muxer); s->is_svcd = (CONFIG_MPEG2SVCD_MUXER && ctx->oformat == &ff_mpeg2svcd_muxer); s->is_mpeg2 = ((CONFIG_MPEG2VOB_MUXER && ctx->oformat == &ff_mpeg2vob_muxer) || (CONFIG_MPEG2DVD_MUXER && ctx->oformat == &ff_mpeg2dvd_muxer) || (CONFIG_MPEG2SVCD_MUXER && ctx->oformat == &ff_mpeg2svcd_muxer)); s->is_dvd = (CONFIG_MPEG2DVD_MUXER && ctx->oformat == &ff_mpeg2dvd_muxer); if (ctx->packet_size) { if (ctx->packet_size < 20 || ctx->packet_size > (1 << 23) + 10) { av_log(ctx, AV_LOG_ERROR, "Invalid packet size %d\n", ctx->packet_size); goto fail; } s->packet_size = ctx->packet_size; } else s->packet_size = 2048; if (ctx->max_delay < 0) /* Not set by the caller */ ctx->max_delay = 0; s->vcd_padding_bytes_written = 0; s->vcd_padding_bitrate = 0; s->audio_bound = 0; s->video_bound = 0; mpa_id = AUDIO_ID; ac3_id = AC3_ID; dts_id = DTS_ID; mpv_id = VIDEO_ID; h264_id = H264_ID; mps_id = SUB_ID; lpcm_id = LPCM_ID; for (i = 0; i < ctx->nb_streams; i++) { AVCPBProperties *props; st = ctx->streams[i]; stream = av_mallocz(sizeof(StreamInfo)); if (!stream) goto fail; st->priv_data = stream; avpriv_set_pts_info(st, 64, 1, 90000); switch (st->codecpar->codec_type) { case AVMEDIA_TYPE_AUDIO: if (st->codecpar->codec_id == AV_CODEC_ID_AC3) { stream->id = ac3_id++; } else if (st->codecpar->codec_id == AV_CODEC_ID_DTS) { stream->id = dts_id++; } else if (st->codecpar->codec_id == AV_CODEC_ID_PCM_S16BE) { stream->id = lpcm_id++; for (j = 0; j < 4; j++) { if (lpcm_freq_tab[j] == st->codecpar->sample_rate) break; } if (j == 4) goto fail; if (st->codecpar->channels > 8) return -1; stream->lpcm_header[0] = 0x0c; stream->lpcm_header[1] = (st->codecpar->channels - 1) | (j << 4); stream->lpcm_header[2] = 0x80; stream->lpcm_align = st->codecpar->channels * 2; } else { stream->id = mpa_id++; } /* This value HAS to be used for VCD (see VCD standard, p. IV-7). * Right now it is also used for everything else. */ stream->max_buffer_size = 4 * 1024; s->audio_bound++; break; case AVMEDIA_TYPE_VIDEO: if (st->codecpar->codec_id == AV_CODEC_ID_H264) stream->id = h264_id++; else stream->id = mpv_id++; props = (AVCPBProperties*)av_stream_get_side_data(st, AV_PKT_DATA_CPB_PROPERTIES, NULL); if (props && props->buffer_size) stream->max_buffer_size = 6 * 1024 + props->buffer_size / 8; else { av_log(ctx, AV_LOG_WARNING, "VBV buffer size not set, muxing may fail\n"); // FIXME: this is probably too small as default stream->max_buffer_size = 230 * 1024; } s->video_bound++; break; case AVMEDIA_TYPE_SUBTITLE: stream->id = mps_id++; stream->max_buffer_size = 16 * 1024; break; default: return -1; } stream->fifo = av_fifo_alloc(16); if (!stream->fifo) goto fail; } bitrate = 0; audio_bitrate = 0; video_bitrate = 0; for (i = 0; i < ctx->nb_streams; i++) { AVCPBProperties *props; int codec_rate; st = ctx->streams[i]; stream = (StreamInfo *)st->priv_data; props = (AVCPBProperties*)av_stream_get_side_data(st, AV_PKT_DATA_CPB_PROPERTIES, NULL); if (props) codec_rate = props->max_bitrate; else codec_rate = st->codecpar->bit_rate; if (!codec_rate) codec_rate = (1 << 21) * 8 * 50 / ctx->nb_streams; bitrate += codec_rate; if ((stream->id & 0xe0) == AUDIO_ID) audio_bitrate += codec_rate; else if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) video_bitrate += codec_rate; } if (!s->mux_rate) { /* we increase slightly the bitrate to take into account the * headers. XXX: compute it exactly */ bitrate += bitrate / 20; bitrate += 10000; s->mux_rate = (bitrate + (8 * 50) - 1) / (8 * 50); } if (s->is_vcd) { double overhead_rate; /* The VCD standard mandates that the mux_rate field is 3528 * (see standard p. IV-6). * The value is actually "wrong", i.e. if you calculate * it using the normal formula and the 75 sectors per second transfer * rate you get a different value because the real pack size is 2324, * not 2352. But the standard explicitly specifies that the mux_rate * field in the header must have this value. */ // s->mux_rate = 2352 * 75 / 50; /* = 3528 */ /* The VCD standard states that the muxed stream must be * exactly 75 packs / second (the data rate of a single speed cdrom). * Since the video bitrate (probably 1150000 bits/sec) will be below * the theoretical maximum we have to add some padding packets * to make up for the lower data rate. * (cf. VCD standard p. IV-6 ) */ /* Add the header overhead to the data rate. * 2279 data bytes per audio pack, 2294 data bytes per video pack */ overhead_rate = ((audio_bitrate / 8.0) / 2279) * (2324 - 2279); overhead_rate += ((video_bitrate / 8.0) / 2294) * (2324 - 2294); overhead_rate *= 8; /* Add padding so that the full bitrate is 2324*75 bytes/sec */ s->vcd_padding_bitrate = 2324 * 75 * 8 - (bitrate + overhead_rate); } if (s->is_vcd || s->is_mpeg2) /* every packet */ s->pack_header_freq = 1; else /* every 2 seconds */ s->pack_header_freq = 2 * bitrate / s->packet_size / 8; /* the above seems to make pack_header_freq zero sometimes */ if (s->pack_header_freq == 0) s->pack_header_freq = 1; if (s->is_mpeg2) /* every 200 packets. Need to look at the spec. */ s->system_header_freq = s->pack_header_freq * 40; else if (s->is_vcd) /* the standard mandates that there are only two system headers * in the whole file: one in the first packet of each stream. * (see standard p. IV-7 and IV-8) */ s->system_header_freq = 0x7fffffff; else s->system_header_freq = s->pack_header_freq * 5; for (i = 0; i < ctx->nb_streams; i++) { stream = ctx->streams[i]->priv_data; stream->packet_number = 0; } s->system_header_size = get_system_header_size(ctx); s->last_scr = 0; return 0; fail: for (i = 0; i < ctx->nb_streams; i++) av_free(ctx->streams[i]->priv_data); return AVERROR(ENOMEM); } static inline void put_timestamp(AVIOContext *pb, int id, int64_t timestamp) { avio_w8(pb, (id << 4) | (((timestamp >> 30) & 0x07) << 1) | 1); avio_wb16(pb, (uint16_t)((((timestamp >> 15) & 0x7fff) << 1) | 1)); avio_wb16(pb, (uint16_t)((((timestamp) & 0x7fff) << 1) | 1)); } /* return the number of padding bytes that should be inserted into * the multiplexed stream. */ static int get_vcd_padding_size(AVFormatContext *ctx, int64_t pts) { MpegMuxContext *s = ctx->priv_data; int pad_bytes = 0; if (s->vcd_padding_bitrate > 0 && pts != AV_NOPTS_VALUE) { int64_t full_pad_bytes; // FIXME: this is wrong full_pad_bytes = (int64_t)((s->vcd_padding_bitrate * (pts / 90000.0)) / 8.0); pad_bytes = (int)(full_pad_bytes - s->vcd_padding_bytes_written); if (pad_bytes < 0) /* might happen if we have already padded to a later timestamp. This * can occur if another stream has already advanced further. */ pad_bytes = 0; } return pad_bytes; } /* Write an MPEG padding packet header. */ static void put_padding_packet(AVFormatContext *ctx, AVIOContext *pb, int packet_bytes) { MpegMuxContext *s = ctx->priv_data; int i; avio_wb32(pb, PADDING_STREAM); avio_wb16(pb, packet_bytes - 6); if (!s->is_mpeg2) { avio_w8(pb, 0x0f); packet_bytes -= 7; } else packet_bytes -= 6; for (i = 0; i < packet_bytes; i++) avio_w8(pb, 0xff); } static int get_nb_frames(AVFormatContext *ctx, StreamInfo *stream, int len) { int nb_frames = 0; PacketDesc *pkt_desc = stream->premux_packet; while (len > 0) { if (pkt_desc->size == pkt_desc->unwritten_size) nb_frames++; len -= pkt_desc->unwritten_size; pkt_desc = pkt_desc->next; } return nb_frames; } /* flush the packet on stream stream_index */ static int flush_packet(AVFormatContext *ctx, int stream_index, int64_t pts, int64_t dts, int64_t scr, int trailer_size) { MpegMuxContext *s = ctx->priv_data; StreamInfo *stream = ctx->streams[stream_index]->priv_data; uint8_t *buf_ptr; int size, payload_size, startcode, id, stuffing_size, i, header_len; int packet_size; uint8_t buffer[128]; int zero_trail_bytes = 0; int pad_packet_bytes = 0; int pes_flags; /* "general" pack without data specific to one stream? */ int general_pack = 0; int nb_frames; id = stream->id; av_log(ctx, AV_LOG_TRACE, "packet ID=%2x PTS=%0.3f\n", id, pts / 90000.0); buf_ptr = buffer; if ((s->packet_number % s->pack_header_freq) == 0 || s->last_scr != scr) { /* output pack and systems header if needed */ size = put_pack_header(ctx, buf_ptr, scr); buf_ptr += size; s->last_scr = scr; if (s->is_vcd) { /* there is exactly one system header for each stream in a VCD MPEG, * One in the very first video packet and one in the very first * audio packet (see VCD standard p. IV-7 and IV-8). */ if (stream->packet_number == 0) { size = put_system_header(ctx, buf_ptr, id); buf_ptr += size; } } else if (s->is_dvd) { if (stream->align_iframe || s->packet_number == 0) { int PES_bytes_to_fill = s->packet_size - size - 10; if (pts != AV_NOPTS_VALUE) { if (dts != pts) PES_bytes_to_fill -= 5 + 5; else PES_bytes_to_fill -= 5; } if (stream->bytes_to_iframe == 0 || s->packet_number == 0) { size = put_system_header(ctx, buf_ptr, 0); buf_ptr += size; size = buf_ptr - buffer; avio_write(ctx->pb, buffer, size); avio_wb32(ctx->pb, PRIVATE_STREAM_2); avio_wb16(ctx->pb, 0x03d4); // length avio_w8(ctx->pb, 0x00); // substream ID, 00=PCI for (i = 0; i < 979; i++) avio_w8(ctx->pb, 0x00); avio_wb32(ctx->pb, PRIVATE_STREAM_2); avio_wb16(ctx->pb, 0x03fa); // length avio_w8(ctx->pb, 0x01); // substream ID, 01=DSI for (i = 0; i < 1017; i++) avio_w8(ctx->pb, 0x00); memset(buffer, 0, 128); buf_ptr = buffer; s->packet_number++; stream->align_iframe = 0; // FIXME: rounding and first few bytes of each packet scr += s->packet_size * 90000LL / (s->mux_rate * 50LL); size = put_pack_header(ctx, buf_ptr, scr); s->last_scr = scr; buf_ptr += size; /* GOP Start */ } else if (stream->bytes_to_iframe < PES_bytes_to_fill) { pad_packet_bytes = PES_bytes_to_fill - stream->bytes_to_iframe; } } } else { if ((s->packet_number % s->system_header_freq) == 0) { size = put_system_header(ctx, buf_ptr, 0); buf_ptr += size; } } } size = buf_ptr - buffer; avio_write(ctx->pb, buffer, size); packet_size = s->packet_size - size; if (s->is_vcd && (id & 0xe0) == AUDIO_ID) /* The VCD standard demands that 20 zero bytes follow * each audio pack (see standard p. IV-8). */ zero_trail_bytes += 20; if ((s->is_vcd && stream->packet_number == 0) || (s->is_svcd && s->packet_number == 0)) { /* for VCD the first pack of each stream contains only the pack header, * the system header and lots of padding (see VCD standard p. IV-6). * In the case of an audio pack, 20 zero bytes are also added at * the end. */ /* For SVCD we fill the very first pack to increase compatibility with * some DVD players. Not mandated by the standard. */ if (s->is_svcd) /* the system header refers to both streams and no stream data */ general_pack = 1; pad_packet_bytes = packet_size - zero_trail_bytes; } packet_size -= pad_packet_bytes + zero_trail_bytes; if (packet_size > 0) { /* packet header size */ packet_size -= 6; /* packet header */ if (s->is_mpeg2) { header_len = 3; if (stream->packet_number == 0) header_len += 3; /* PES extension */ header_len += 1; /* obligatory stuffing byte */ } else { header_len = 0; } if (pts != AV_NOPTS_VALUE) { if (dts != pts) header_len += 5 + 5; else header_len += 5; } else { if (!s->is_mpeg2) header_len++; } payload_size = packet_size - header_len; if (id < 0xc0) { startcode = PRIVATE_STREAM_1; payload_size -= 1; if (id >= 0x40) { payload_size -= 3; if (id >= 0xa0) payload_size -= 3; } } else { startcode = 0x100 + id; } stuffing_size = payload_size - av_fifo_size(stream->fifo); // first byte does not fit -> reset pts/dts + stuffing if (payload_size <= trailer_size && pts != AV_NOPTS_VALUE) { int timestamp_len = 0; if (dts != pts) timestamp_len += 5; if (pts != AV_NOPTS_VALUE) timestamp_len += s->is_mpeg2 ? 5 : 4; pts = dts = AV_NOPTS_VALUE; header_len -= timestamp_len; if (s->is_dvd && stream->align_iframe) { pad_packet_bytes += timestamp_len; packet_size -= timestamp_len; } else { payload_size += timestamp_len; } stuffing_size += timestamp_len; if (payload_size > trailer_size) stuffing_size += payload_size - trailer_size; } // can't use padding, so use stuffing if (pad_packet_bytes > 0 && pad_packet_bytes <= 7) { packet_size += pad_packet_bytes; payload_size += pad_packet_bytes; // undo the previous adjustment if (stuffing_size < 0) stuffing_size = pad_packet_bytes; else stuffing_size += pad_packet_bytes; pad_packet_bytes = 0; } if (stuffing_size < 0) stuffing_size = 0; if (startcode == PRIVATE_STREAM_1 && id >= 0xa0) { if (payload_size < av_fifo_size(stream->fifo)) stuffing_size += payload_size % stream->lpcm_align; } if (stuffing_size > 16) { /* <=16 for MPEG-1, <=32 for MPEG-2 */ pad_packet_bytes += stuffing_size; packet_size -= stuffing_size; payload_size -= stuffing_size; stuffing_size = 0; } nb_frames = get_nb_frames(ctx, stream, payload_size - stuffing_size); avio_wb32(ctx->pb, startcode); avio_wb16(ctx->pb, packet_size); if (!s->is_mpeg2) for (i = 0; i < stuffing_size; i++) avio_w8(ctx->pb, 0xff); if (s->is_mpeg2) { avio_w8(ctx->pb, 0x80); /* mpeg2 id */ pes_flags = 0; if (pts != AV_NOPTS_VALUE) { pes_flags |= 0x80; if (dts != pts) pes_flags |= 0x40; } /* Both the MPEG-2 and the SVCD standards demand that the * P-STD_buffer_size field be included in the first packet of * every stream. (see SVCD standard p. 26 V.2.3.1 and V.2.3.2 * and MPEG-2 standard 2.7.7) */ if (stream->packet_number == 0) pes_flags |= 0x01; avio_w8(ctx->pb, pes_flags); /* flags */ avio_w8(ctx->pb, header_len - 3 + stuffing_size); if (pes_flags & 0x80) /* write pts */ put_timestamp(ctx->pb, (pes_flags & 0x40) ? 0x03 : 0x02, pts); if (pes_flags & 0x40) /* write dts */ put_timestamp(ctx->pb, 0x01, dts); if (pes_flags & 0x01) { /* write pes extension */ avio_w8(ctx->pb, 0x10); /* flags */ /* P-STD buffer info */ if ((id & 0xe0) == AUDIO_ID) avio_wb16(ctx->pb, 0x4000 | stream->max_buffer_size / 128); else avio_wb16(ctx->pb, 0x6000 | stream->max_buffer_size / 1024); } } else { if (pts != AV_NOPTS_VALUE) { if (dts != pts) { put_timestamp(ctx->pb, 0x03, pts); put_timestamp(ctx->pb, 0x01, dts); } else { put_timestamp(ctx->pb, 0x02, pts); } } else { avio_w8(ctx->pb, 0x0f); } } if (s->is_mpeg2) { /* special stuffing byte that is always written * to prevent accidental generation of start codes. */ avio_w8(ctx->pb, 0xff); for (i = 0; i < stuffing_size; i++) avio_w8(ctx->pb, 0xff); } if (startcode == PRIVATE_STREAM_1) { avio_w8(ctx->pb, id); if (id >= 0xa0) { /* LPCM (XXX: check nb_frames) */ avio_w8(ctx->pb, 7); avio_wb16(ctx->pb, 4); /* skip 3 header bytes */ avio_w8(ctx->pb, stream->lpcm_header[0]); avio_w8(ctx->pb, stream->lpcm_header[1]); avio_w8(ctx->pb, stream->lpcm_header[2]); } else if (id >= 0x40) { /* AC-3 */ avio_w8(ctx->pb, nb_frames); avio_wb16(ctx->pb, trailer_size + 1); } } /* output data */ assert(payload_size - stuffing_size <= av_fifo_size(stream->fifo)); av_fifo_generic_read(stream->fifo, ctx->pb, payload_size - stuffing_size, (void (*)(void*, void*, int))avio_write); stream->bytes_to_iframe -= payload_size - stuffing_size; } else { payload_size = stuffing_size = 0; } if (pad_packet_bytes > 0) put_padding_packet(ctx, ctx->pb, pad_packet_bytes); for (i = 0; i < zero_trail_bytes; i++) avio_w8(ctx->pb, 0x00); avio_flush(ctx->pb); s->packet_number++; /* only increase the stream packet number if this pack actually contains * something that is specific to this stream! I.e. a dedicated header * or some data. */ if (!general_pack) stream->packet_number++; return payload_size - stuffing_size; } static void put_vcd_padding_sector(AVFormatContext *ctx) { /* There are two ways to do this padding: writing a sector/pack * of 0 values, or writing an MPEG padding pack. Both seem to * work with most decoders, BUT the VCD standard only allows a 0-sector * (see standard p. IV-4, IV-5). * So a 0-sector it is... */ MpegMuxContext *s = ctx->priv_data; int i; for (i = 0; i < s->packet_size; i++) avio_w8(ctx->pb, 0); s->vcd_padding_bytes_written += s->packet_size; avio_flush(ctx->pb); /* increasing the packet number is correct. The SCR of the following packs * is calculated from the packet_number and it has to include the padding * sector (it represents the sector index, not the MPEG pack index) * (see VCD standard p. IV-6) */ s->packet_number++; } static int remove_decoded_packets(AVFormatContext *ctx, int64_t scr) { int i; for (i = 0; i < ctx->nb_streams; i++) { AVStream *st = ctx->streams[i]; StreamInfo *stream = st->priv_data; PacketDesc *pkt_desc; while ((pkt_desc = stream->predecode_packet) && scr > pkt_desc->dts) { // FIXME: > vs >= if (stream->buffer_index < pkt_desc->size || stream->predecode_packet == stream->premux_packet) { av_log(ctx, AV_LOG_ERROR, "buffer underflow i=%d bufi=%d size=%d\n", i, stream->buffer_index, pkt_desc->size); break; } stream->buffer_index -= pkt_desc->size; stream->predecode_packet = pkt_desc->next; av_freep(&pkt_desc); } } return 0; } static int output_packet(AVFormatContext *ctx, int flush) { MpegMuxContext *s = ctx->priv_data; AVStream *st; StreamInfo *stream; int i, avail_space = 0, es_size, trailer_size; int best_i = -1; int best_score = INT_MIN; int ignore_constraints = 0; int64_t scr = s->last_scr; PacketDesc *timestamp_packet; const int64_t max_delay = av_rescale(ctx->max_delay, 90000, AV_TIME_BASE); retry: for (i = 0; i < ctx->nb_streams; i++) { AVStream *st = ctx->streams[i]; StreamInfo *stream = st->priv_data; const int avail_data = av_fifo_size(stream->fifo); const int space = stream->max_buffer_size - stream->buffer_index; int rel_space = 1024 * space / stream->max_buffer_size; PacketDesc *next_pkt = stream->premux_packet; /* for subtitle, a single PES packet must be generated, * so we flush after every single subtitle packet */ if (s->packet_size > avail_data && !flush && st->codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE) return 0; if (avail_data == 0) continue; assert(avail_data > 0); if (space < s->packet_size && !ignore_constraints) continue; if (next_pkt && next_pkt->dts - scr > max_delay) continue; if (rel_space > best_score) { best_score = rel_space; best_i = i; avail_space = space; } } if (best_i < 0) { int64_t best_dts = INT64_MAX; for (i = 0; i < ctx->nb_streams; i++) { AVStream *st = ctx->streams[i]; StreamInfo *stream = st->priv_data; PacketDesc *pkt_desc = stream->predecode_packet; if (pkt_desc && pkt_desc->dts < best_dts) best_dts = pkt_desc->dts; } av_log(ctx, AV_LOG_TRACE, "bumping scr, scr:%f, dts:%f\n", scr / 90000.0, best_dts / 90000.0); if (best_dts == INT64_MAX) return 0; if (scr >= best_dts + 1 && !ignore_constraints) { av_log(ctx, AV_LOG_ERROR, "packet too large, ignoring buffer limits to mux it\n"); ignore_constraints = 1; } scr = FFMAX(best_dts + 1, scr); if (remove_decoded_packets(ctx, scr) < 0) return -1; goto retry; } assert(best_i >= 0); st = ctx->streams[best_i]; stream = st->priv_data; assert(av_fifo_size(stream->fifo) > 0); assert(avail_space >= s->packet_size || ignore_constraints); timestamp_packet = stream->premux_packet; if (timestamp_packet->unwritten_size == timestamp_packet->size) { trailer_size = 0; } else { trailer_size = timestamp_packet->unwritten_size; timestamp_packet = timestamp_packet->next; } if (timestamp_packet) { av_log(ctx, AV_LOG_TRACE, "dts:%f pts:%f scr:%f stream:%d\n", timestamp_packet->dts / 90000.0, timestamp_packet->pts / 90000.0, scr / 90000.0, best_i); es_size = flush_packet(ctx, best_i, timestamp_packet->pts, timestamp_packet->dts, scr, trailer_size); } else { assert(av_fifo_size(stream->fifo) == trailer_size); es_size = flush_packet(ctx, best_i, AV_NOPTS_VALUE, AV_NOPTS_VALUE, scr, trailer_size); } if (s->is_vcd) { /* Write one or more padding sectors, if necessary, to reach * the constant overall bitrate. */ int vcd_pad_bytes; // FIXME: pts cannot be correct here while ((vcd_pad_bytes = get_vcd_padding_size(ctx, stream->premux_packet->pts)) >= s->packet_size) { put_vcd_padding_sector(ctx); // FIXME: rounding and first few bytes of each packet s->last_scr += s->packet_size * 90000LL / (s->mux_rate * 50LL); } } stream->buffer_index += es_size; // FIXME: rounding and first few bytes of each packet s->last_scr += s->packet_size * 90000LL / (s->mux_rate * 50LL); while (stream->premux_packet && stream->premux_packet->unwritten_size <= es_size) { es_size -= stream->premux_packet->unwritten_size; stream->premux_packet = stream->premux_packet->next; } if (stream->premux_packet && es_size) stream->premux_packet->unwritten_size -= es_size; if (remove_decoded_packets(ctx, s->last_scr) < 0) return -1; return 1; } static int mpeg_mux_write_packet(AVFormatContext *ctx, AVPacket *pkt) { int stream_index = pkt->stream_index; int size = pkt->size; uint8_t *buf = pkt->data; MpegMuxContext *s = ctx->priv_data; AVStream *st = ctx->streams[stream_index]; StreamInfo *stream = st->priv_data; int64_t pts, dts; PacketDesc *pkt_desc; int preload; const int is_iframe = st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && (pkt->flags & AV_PKT_FLAG_KEY); preload = av_rescale(s->preload, 90000, AV_TIME_BASE); pts = pkt->pts; dts = pkt->dts; if (pts != AV_NOPTS_VALUE) pts += 2 * preload; if (dts != AV_NOPTS_VALUE) { if (!s->last_scr) s->last_scr = dts + preload; dts += 2 * preload; } av_log(ctx, AV_LOG_TRACE, "dts:%f pts:%f flags:%d stream:%d nopts:%d\n", dts / 90000.0, pts / 90000.0, pkt->flags, pkt->stream_index, pts != AV_NOPTS_VALUE); if (!stream->premux_packet) stream->next_packet = &stream->premux_packet; *stream->next_packet = pkt_desc = av_mallocz(sizeof(PacketDesc)); pkt_desc->pts = pts; pkt_desc->dts = dts; pkt_desc->unwritten_size = pkt_desc->size = size; if (!stream->predecode_packet) stream->predecode_packet = pkt_desc; stream->next_packet = &pkt_desc->next; if (av_fifo_realloc2(stream->fifo, av_fifo_size(stream->fifo) + size) < 0) return -1; if (s->is_dvd) { // min VOBU length 0.4 seconds (mpucoder) if (is_iframe && (s->packet_number == 0 || (pts - stream->vobu_start_pts >= 36000))) { stream->bytes_to_iframe = av_fifo_size(stream->fifo); stream->align_iframe = 1; stream->vobu_start_pts = pts; } } av_fifo_generic_write(stream->fifo, buf, size, NULL); for (;;) { int ret = output_packet(ctx, 0); if (ret <= 0) return ret; } } static int mpeg_mux_end(AVFormatContext *ctx) { StreamInfo *stream; int i; for (;;) { int ret = output_packet(ctx, 1); if (ret < 0) return ret; else if (ret == 0) break; } /* End header according to MPEG-1 systems standard. We do not write * it as it is usually not needed by decoders and because it * complicates MPEG stream concatenation. */ // avio_wb32(ctx->pb, ISO_11172_END_CODE); // avio_flush(ctx->pb); for (i = 0; i < ctx->nb_streams; i++) { stream = ctx->streams[i]->priv_data; assert(av_fifo_size(stream->fifo) == 0); av_fifo_free(stream->fifo); } return 0; } #define OFFSET(x) offsetof(MpegMuxContext, x) #define E AV_OPT_FLAG_ENCODING_PARAM static const AVOption options[] = { { "muxrate", NULL, OFFSET(mux_rate), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, (1 << 22) - 1, E }, { "preload", "Initial demux-decode delay in microseconds.", OFFSET(preload), AV_OPT_TYPE_INT, { .i64 = 500000 }, 0, INT_MAX, E }, { NULL }, }; #define MPEGENC_CLASS(flavor) \ static const AVClass flavor ## _class = { \ .class_name = #flavor " muxer", \ .item_name = av_default_item_name, \ .version = LIBAVUTIL_VERSION_INT, \ .option = options, \ }; #if CONFIG_MPEG1SYSTEM_MUXER MPEGENC_CLASS(mpeg) AVOutputFormat ff_mpeg1system_muxer = { .name = "mpeg", .long_name = NULL_IF_CONFIG_SMALL("MPEG-1 Systems / MPEG program stream"), .mime_type = "video/mpeg", .extensions = "mpg,mpeg", .priv_data_size = sizeof(MpegMuxContext), .audio_codec = AV_CODEC_ID_MP2, .video_codec = AV_CODEC_ID_MPEG1VIDEO, .write_header = mpeg_mux_init, .write_packet = mpeg_mux_write_packet, .write_trailer = mpeg_mux_end, .priv_class = &mpeg_class, }; #endif #if CONFIG_MPEG1VCD_MUXER MPEGENC_CLASS(vcd) AVOutputFormat ff_mpeg1vcd_muxer = { .name = "vcd", .long_name = NULL_IF_CONFIG_SMALL("MPEG-1 Systems / MPEG program stream (VCD)"), .mime_type = "video/mpeg", .priv_data_size = sizeof(MpegMuxContext), .audio_codec = AV_CODEC_ID_MP2, .video_codec = AV_CODEC_ID_MPEG1VIDEO, .write_header = mpeg_mux_init, .write_packet = mpeg_mux_write_packet, .write_trailer = mpeg_mux_end, .priv_class = &vcd_class, }; #endif #if CONFIG_MPEG2VOB_MUXER MPEGENC_CLASS(vob) AVOutputFormat ff_mpeg2vob_muxer = { .name = "vob", .long_name = NULL_IF_CONFIG_SMALL("MPEG-2 PS (VOB)"), .mime_type = "video/mpeg", .extensions = "vob", .priv_data_size = sizeof(MpegMuxContext), .audio_codec = AV_CODEC_ID_MP2, .video_codec = AV_CODEC_ID_MPEG2VIDEO, .write_header = mpeg_mux_init, .write_packet = mpeg_mux_write_packet, .write_trailer = mpeg_mux_end, .priv_class = &vob_class, }; #endif /* Same as mpeg2vob_mux except that the pack size is 2324 */ #if CONFIG_MPEG2SVCD_MUXER MPEGENC_CLASS(svcd) AVOutputFormat ff_mpeg2svcd_muxer = { .name = "svcd", .long_name = NULL_IF_CONFIG_SMALL("MPEG-2 PS (SVCD)"), .mime_type = "video/mpeg", .extensions = "vob", .priv_data_size = sizeof(MpegMuxContext), .audio_codec = AV_CODEC_ID_MP2, .video_codec = AV_CODEC_ID_MPEG2VIDEO, .write_header = mpeg_mux_init, .write_packet = mpeg_mux_write_packet, .write_trailer = mpeg_mux_end, .priv_class = &svcd_class, }; #endif /* Same as mpeg2vob_mux except the 'is_dvd' flag is set to produce NAV pkts */ #if CONFIG_MPEG2DVD_MUXER MPEGENC_CLASS(dvd) AVOutputFormat ff_mpeg2dvd_muxer = { .name = "dvd", .long_name = NULL_IF_CONFIG_SMALL("MPEG-2 PS (DVD VOB)"), .mime_type = "video/mpeg", .extensions = "dvd", .priv_data_size = sizeof(MpegMuxContext), .audio_codec = AV_CODEC_ID_MP2, .video_codec = AV_CODEC_ID_MPEG2VIDEO, .write_header = mpeg_mux_init, .write_packet = mpeg_mux_write_packet, .write_trailer = mpeg_mux_end, .priv_class = &dvd_class, }; #endif