+++ /dev/null
-/*
- * MPEG1/2 mux/demux
- * Copyright (c) 2000, 2001, 2002 Fabrice Bellard.
- *
- * This library 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 of the License, or (at your option) any later version.
- *
- * This library 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 this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-#include "avformat.h"
-
-#define MAX_PAYLOAD_SIZE 4096
-#define NB_STREAMS 2
-
-typedef struct {
- uint8_t buffer[MAX_PAYLOAD_SIZE];
- int buffer_ptr;
- uint8_t id;
- int max_buffer_size; /* in bytes */
- int packet_number;
- int64_t start_pts;
-} StreamInfo;
-
-typedef struct {
- int packet_size; /* required packet size */
- int packet_data_max_size; /* maximum data size inside a packet */
- int packet_number;
- int pack_header_freq; /* frequency (in packets^-1) at which we send pack headers */
- int system_header_freq;
- int mux_rate; /* bitrate in units of 50 bytes/s */
- /* stream info */
- int audio_bound;
- int video_bound;
- int is_mpeg2;
- int is_vcd;
-} MpegMuxContext;
-
-#define PACK_START_CODE ((unsigned int)0x000001ba)
-#define SYSTEM_HEADER_START_CODE ((unsigned int)0x000001bb)
-#define SEQUENCE_END_CODE ((unsigned int)0x000001b7)
-#define PACKET_START_CODE_MASK ((unsigned int)0xffffff00)
-#define PACKET_START_CODE_PREFIX ((unsigned int)0x00000100)
-#define ISO_11172_END_CODE ((unsigned int)0x000001b9)
-
-/* mpeg2 */
-#define PROGRAM_STREAM_MAP 0x1bc
-#define PRIVATE_STREAM_1 0x1bd
-#define PADDING_STREAM 0x1be
-#define PRIVATE_STREAM_2 0x1bf
-
-
-#define AUDIO_ID 0xc0
-#define VIDEO_ID 0xe0
-
-extern AVOutputFormat mpeg1system_mux;
-extern AVOutputFormat mpeg1vcd_mux;
-extern AVOutputFormat mpeg2vob_mux;
-
-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, NULL, NULL);
-
- put_bits(&pb, 32, 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, 1, 1);
- put_bits(&pb, 22, s->mux_rate);
- put_bits(&pb, 1, 1);
- if (s->is_mpeg2) {
- put_bits(&pb, 5, 0x1f); /* reserved */
- put_bits(&pb, 3, 0); /* stuffing length */
- }
- flush_put_bits(&pb);
- return pbBufPtr(&pb) - pb.buf;
-}
-
-static int put_system_header(AVFormatContext *ctx, uint8_t *buf)
-{
- MpegMuxContext *s = ctx->priv_data;
- int size, rate_bound, i, private_stream_coded, id;
- PutBitContext pb;
-
- init_put_bits(&pb, buf, 128, NULL, NULL);
-
- put_bits(&pb, 32, SYSTEM_HEADER_START_CODE);
- put_bits(&pb, 16, 0);
- put_bits(&pb, 1, 1);
-
- rate_bound = s->mux_rate; /* maximum bit rate of the multiplexed stream */
- put_bits(&pb, 22, rate_bound);
- put_bits(&pb, 1, 1); /* marker */
- put_bits(&pb, 6, s->audio_bound);
-
- put_bits(&pb, 1, 1); /* variable bitrate */
- put_bits(&pb, 1, 1); /* non constrainted bit stream */
-
- put_bits(&pb, 1, 0); /* audio locked */
- put_bits(&pb, 1, 0); /* video locked */
- put_bits(&pb, 1, 1); /* marker */
-
- put_bits(&pb, 5, s->video_bound);
- put_bits(&pb, 8, 0xff); /* reserved byte */
-
- /* audio stream info */
- private_stream_coded = 0;
- for(i=0;i<ctx->nb_streams;i++) {
- StreamInfo *stream = ctx->streams[i]->priv_data;
- id = stream->id;
- if (id < 0xc0) {
- /* special case for private streams (AC3 use 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 = pbBufPtr(&pb) - pb.buf;
- /* patch packet size */
- buf[4] = (size - 6) >> 8;
- buf[5] = (size - 6) & 0xff;
-
- return size;
-}
-
-static int mpeg_mux_init(AVFormatContext *ctx)
-{
- MpegMuxContext *s = ctx->priv_data;
- int bitrate, i, mpa_id, mpv_id, ac3_id;
- AVStream *st;
- StreamInfo *stream;
-
- s->packet_number = 0;
- s->is_vcd = (ctx->oformat == &mpeg1vcd_mux);
- s->is_mpeg2 = (ctx->oformat == &mpeg2vob_mux);
-
- if (s->is_vcd)
- s->packet_size = 2324; /* VCD packet size */
- else
- s->packet_size = 2048;
-
- /* startcode(4) + length(2) + flags(1) */
- s->packet_data_max_size = s->packet_size - 7;
- s->audio_bound = 0;
- s->video_bound = 0;
- mpa_id = AUDIO_ID;
- ac3_id = 0x80;
- mpv_id = VIDEO_ID;
- for(i=0;i<ctx->nb_streams;i++) {
- st = ctx->streams[i];
- stream = av_mallocz(sizeof(StreamInfo));
- if (!stream)
- goto fail;
- st->priv_data = stream;
-
- switch(st->codec.codec_type) {
- case CODEC_TYPE_AUDIO:
- if (st->codec.codec_id == CODEC_ID_AC3)
- stream->id = ac3_id++;
- else
- stream->id = mpa_id++;
- stream->max_buffer_size = 4 * 1024;
- s->audio_bound++;
- break;
- case CODEC_TYPE_VIDEO:
- stream->id = mpv_id++;
- stream->max_buffer_size = 46 * 1024;
- s->video_bound++;
- break;
- default:
- av_abort();
- }
- }
-
- /* we increase slightly the bitrate to take into account the
- headers. XXX: compute it exactly */
- bitrate = 2000;
- for(i=0;i<ctx->nb_streams;i++) {
- st = ctx->streams[i];
- bitrate += st->codec.bit_rate;
- }
- s->mux_rate = (bitrate + (8 * 50) - 1) / (8 * 50);
-
- 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;
-
- 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)
- /* every 40 packets, this is my invention */
- s->system_header_freq = s->pack_header_freq * 40;
- 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->buffer_ptr = 0;
- stream->packet_number = 0;
- stream->start_pts = -1;
- }
- return 0;
- fail:
- for(i=0;i<ctx->nb_streams;i++) {
- av_free(ctx->streams[i]->priv_data);
- }
- return -ENOMEM;
-}
-
-/* flush the packet on stream stream_index */
-static void flush_packet(AVFormatContext *ctx, int stream_index)
-{
- MpegMuxContext *s = ctx->priv_data;
- StreamInfo *stream = ctx->streams[stream_index]->priv_data;
- uint8_t *buf_ptr;
- int size, payload_size, startcode, id, len, stuffing_size, i, header_len;
- int64_t timestamp;
- uint8_t buffer[128];
-
- id = stream->id;
- timestamp = stream->start_pts;
-
-#if 0
- printf("packet ID=%2x PTS=%0.3f\n",
- id, timestamp / 90000.0);
-#endif
-
- buf_ptr = buffer;
- if (((s->packet_number % s->pack_header_freq) == 0)) {
- /* output pack and systems header if needed */
- size = put_pack_header(ctx, buf_ptr, timestamp);
- buf_ptr += size;
- if ((s->packet_number % s->system_header_freq) == 0) {
- size = put_system_header(ctx, buf_ptr);
- buf_ptr += size;
- }
- }
- size = buf_ptr - buffer;
- put_buffer(&ctx->pb, buffer, size);
-
- /* packet header */
- if (s->is_mpeg2) {
- header_len = 8;
- } else {
- header_len = 5;
- }
- payload_size = s->packet_size - (size + 6 + header_len);
- if (id < 0xc0) {
- startcode = PRIVATE_STREAM_1;
- payload_size -= 4;
- } else {
- startcode = 0x100 + id;
- }
- stuffing_size = payload_size - stream->buffer_ptr;
- if (stuffing_size < 0)
- stuffing_size = 0;
-
- put_be32(&ctx->pb, startcode);
-
- put_be16(&ctx->pb, payload_size + header_len);
- /* stuffing */
- for(i=0;i<stuffing_size;i++)
- put_byte(&ctx->pb, 0xff);
-
- if (s->is_mpeg2) {
- put_byte(&ctx->pb, 0x80); /* mpeg2 id */
- put_byte(&ctx->pb, 0x80); /* flags */
- put_byte(&ctx->pb, 0x05); /* header len (only pts is included) */
- }
- put_byte(&ctx->pb,
- (0x02 << 4) |
- (((timestamp >> 30) & 0x07) << 1) |
- 1);
- put_be16(&ctx->pb, (uint16_t)((((timestamp >> 15) & 0x7fff) << 1) | 1));
- put_be16(&ctx->pb, (uint16_t)((((timestamp) & 0x7fff) << 1) | 1));
-
- if (startcode == PRIVATE_STREAM_1) {
- put_byte(&ctx->pb, id);
- if (id >= 0x80 && id <= 0xbf) {
- /* XXX: need to check AC3 spec */
- put_byte(&ctx->pb, 1);
- put_byte(&ctx->pb, 0);
- put_byte(&ctx->pb, 2);
- }
- }
-
- /* output data */
- put_buffer(&ctx->pb, stream->buffer, payload_size - stuffing_size);
- put_flush_packet(&ctx->pb);
-
- /* preserve remaining data */
- len = stream->buffer_ptr - payload_size;
- if (len < 0)
- len = 0;
- memmove(stream->buffer, stream->buffer + stream->buffer_ptr - len, len);
- stream->buffer_ptr = len;
-
- s->packet_number++;
- stream->packet_number++;
- stream->start_pts = -1;
-}
-
-static int mpeg_mux_write_packet(AVFormatContext *ctx, int stream_index,
- const uint8_t *buf, int size, int64_t pts)
-{
- MpegMuxContext *s = ctx->priv_data;
- AVStream *st = ctx->streams[stream_index];
- StreamInfo *stream = st->priv_data;
- int len;
-
- while (size > 0) {
- /* set pts */
- if (stream->start_pts == -1) {
- stream->start_pts = pts;
- }
- len = s->packet_data_max_size - stream->buffer_ptr;
- if (len > size)
- len = size;
- memcpy(stream->buffer + stream->buffer_ptr, buf, len);
- stream->buffer_ptr += len;
- buf += len;
- size -= len;
- while (stream->buffer_ptr >= s->packet_data_max_size) {
- /* output the packet */
- if (stream->start_pts == -1)
- stream->start_pts = pts;
- flush_packet(ctx, stream_index);
- }
- }
- return 0;
-}
-
-static int mpeg_mux_end(AVFormatContext *ctx)
-{
- StreamInfo *stream;
- int i;
-
- /* flush each packet */
- for(i=0;i<ctx->nb_streams;i++) {
- stream = ctx->streams[i]->priv_data;
- if (stream->buffer_ptr > 0) {
- flush_packet(ctx, i);
- }
- }
-
- /* End header according to MPEG1 systems standard. We do not write
- it as it is usually not needed by decoders and because it
- complicates MPEG stream concatenation. */
- //put_be32(&ctx->pb, ISO_11172_END_CODE);
- //put_flush_packet(&ctx->pb);
-
- for(i=0;i<ctx->nb_streams;i++)
- av_freep(&ctx->streams[i]->priv_data);
-
- return 0;
-}
-
-/*********************************************/
-/* demux code */
-
-#define MAX_SYNC_SIZE 100000
-
-static int mpegps_probe(AVProbeData *p)
-{
- int code, c, i;
-
- code = 0xff;
- /* we search the first start code. If it is a packet start code,
- then we decide it is mpeg ps. We do not send highest value to
- give a chance to mpegts */
- /* NOTE: the search range was restricted to avoid too many false
- detections */
-
- if (p->buf_size < 6)
- return 0;
-
- for (i = 0; i < 20; i++) {
- c = p->buf[i];
- code = (code << 8) | c;
- if ((code & 0xffffff00) == 0x100) {
- if (code == PACK_START_CODE ||
- code == SYSTEM_HEADER_START_CODE ||
- (code >= 0x1e0 && code <= 0x1ef) ||
- (code >= 0x1c0 && code <= 0x1df) ||
- code == PRIVATE_STREAM_2 ||
- code == PROGRAM_STREAM_MAP ||
- code == PRIVATE_STREAM_1 ||
- code == PADDING_STREAM)
- return AVPROBE_SCORE_MAX - 2;
- else
- return 0;
- }
- }
- return 0;
-}
-
-
-typedef struct MpegDemuxContext {
- int header_state;
-} MpegDemuxContext;
-
-static int find_start_code(ByteIOContext *pb, int *size_ptr,
- uint32_t *header_state)
-{
- unsigned int state, v;
- int val, n;
-
- state = *header_state;
- n = *size_ptr;
- while (n > 0) {
- if (url_feof(pb))
- break;
- v = get_byte(pb);
- n--;
- if (state == 0x000001) {
- state = ((state << 8) | v) & 0xffffff;
- val = state;
- goto found;
- }
- state = ((state << 8) | v) & 0xffffff;
- }
- val = -1;
- found:
- *header_state = state;
- *size_ptr = n;
- return val;
-}
-
-static int mpegps_read_header(AVFormatContext *s,
- AVFormatParameters *ap)
-{
- MpegDemuxContext *m = s->priv_data;
- m->header_state = 0xff;
- /* no need to do more */
- return 0;
-}
-
-static int64_t get_pts(ByteIOContext *pb, int c)
-{
- int64_t pts;
- int val;
-
- if (c < 0)
- c = get_byte(pb);
- pts = (int64_t)((c >> 1) & 0x07) << 30;
- val = get_be16(pb);
- pts |= (int64_t)(val >> 1) << 15;
- val = get_be16(pb);
- pts |= (int64_t)(val >> 1);
- return pts;
-}
-
-static int mpegps_read_packet(AVFormatContext *s,
- AVPacket *pkt)
-{
- MpegDemuxContext *m = s->priv_data;
- AVStream *st;
- int len, size, startcode, i, c, flags, header_len, type, codec_id;
- int64_t pts, dts;
-
- /* next start code (should be immediately after) */
- redo:
- m->header_state = 0xff;
- size = MAX_SYNC_SIZE;
- startcode = find_start_code(&s->pb, &size, &m->header_state);
- //printf("startcode=%x pos=0x%Lx\n", startcode, url_ftell(&s->pb));
- if (startcode < 0)
- return -EIO;
- if (startcode == PACK_START_CODE)
- goto redo;
- if (startcode == SYSTEM_HEADER_START_CODE)
- goto redo;
- if (startcode == PADDING_STREAM ||
- startcode == PRIVATE_STREAM_2) {
- /* skip them */
- len = get_be16(&s->pb);
- url_fskip(&s->pb, len);
- goto redo;
- }
- /* find matching stream */
- if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
- (startcode >= 0x1e0 && startcode <= 0x1ef) ||
- (startcode == 0x1bd)))
- goto redo;
-
- len = get_be16(&s->pb);
- pts = AV_NOPTS_VALUE;
- dts = AV_NOPTS_VALUE;
- /* stuffing */
- for(;;) {
- c = get_byte(&s->pb);
- len--;
- /* XXX: for mpeg1, should test only bit 7 */
- if (c != 0xff)
- break;
- }
- if ((c & 0xc0) == 0x40) {
- /* buffer scale & size */
- get_byte(&s->pb);
- c = get_byte(&s->pb);
- len -= 2;
- }
- if ((c & 0xf0) == 0x20) {
- pts = get_pts(&s->pb, c);
- len -= 4;
- } else if ((c & 0xf0) == 0x30) {
- pts = get_pts(&s->pb, c);
- dts = get_pts(&s->pb, -1);
- len -= 9;
- } else if ((c & 0xc0) == 0x80) {
- /* mpeg 2 PES */
- if ((c & 0x30) != 0) {
- fprintf(stderr, "Encrypted multiplex not handled\n");
- return -EIO;
- }
- flags = get_byte(&s->pb);
- header_len = get_byte(&s->pb);
- len -= 2;
- if (header_len > len)
- goto redo;
- if ((flags & 0xc0) == 0x80) {
- pts = get_pts(&s->pb, -1);
- header_len -= 5;
- len -= 5;
- } if ((flags & 0xc0) == 0xc0) {
- pts = get_pts(&s->pb, -1);
- dts = get_pts(&s->pb, -1);
- header_len -= 10;
- len -= 10;
- }
- len -= header_len;
- while (header_len > 0) {
- get_byte(&s->pb);
- header_len--;
- }
- }
- if (startcode == 0x1bd) {
- startcode = get_byte(&s->pb);
- len--;
- if (startcode >= 0x80 && startcode <= 0xbf) {
- /* audio: skip header */
- get_byte(&s->pb);
- get_byte(&s->pb);
- get_byte(&s->pb);
- len -= 3;
- }
- }
-
- /* now find stream */
- for(i=0;i<s->nb_streams;i++) {
- st = s->streams[i];
- if (st->id == startcode)
- goto found;
- }
- if (startcode >= 0x1e0 && startcode <= 0x1ef) {
- type = CODEC_TYPE_VIDEO;
- codec_id = CODEC_ID_MPEG1VIDEO;
- } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
- type = CODEC_TYPE_AUDIO;
- codec_id = CODEC_ID_MP2;
- } else if (startcode >= 0x80 && startcode <= 0x9f) {
- type = CODEC_TYPE_AUDIO;
- codec_id = CODEC_ID_AC3;
- } else if (startcode >= 0xa0 && startcode <= 0xbf) {
- type = CODEC_TYPE_AUDIO;
- codec_id = CODEC_ID_PCM_S16BE;
- } else {
- skip:
- /* skip packet */
- url_fskip(&s->pb, len);
- goto redo;
- }
- /* no stream found: add a new stream */
- st = av_new_stream(s, startcode);
- if (!st)
- goto skip;
- st->codec.codec_type = type;
- st->codec.codec_id = codec_id;
- found:
- if (startcode >= 0xa0 && startcode <= 0xbf) {
- int b1, freq;
- static const int lpcm_freq_tab[4] = { 48000, 96000, 44100, 32000 };
-
- /* for LPCM, we just skip the header and consider it is raw
- audio data */
- if (len <= 3)
- goto skip;
- get_byte(&s->pb); /* emphasis (1), muse(1), reserved(1), frame number(5) */
- b1 = get_byte(&s->pb); /* quant (2), freq(2), reserved(1), channels(3) */
- get_byte(&s->pb); /* dynamic range control (0x80 = off) */
- len -= 3;
- freq = (b1 >> 4) & 3;
- st->codec.sample_rate = lpcm_freq_tab[freq];
- st->codec.channels = 1 + (b1 & 7);
- st->codec.bit_rate = st->codec.channels * st->codec.sample_rate * 2;
- }
- av_new_packet(pkt, len);
- //printf("\nRead Packet ID: %x PTS: %f Size: %d", startcode,
- // (float)pts/90000, len);
- get_buffer(&s->pb, pkt->data, pkt->size);
- pkt->pts = pts;
- pkt->stream_index = st->index;
- return 0;
-}
-
-static int mpegps_read_close(AVFormatContext *s)
-{
- return 0;
-}
-
-static AVOutputFormat mpeg1system_mux = {
- "mpeg",
- "MPEG1 System format",
- "video/mpeg",
- "mpg,mpeg",
- sizeof(MpegMuxContext),
- CODEC_ID_MP2,
- CODEC_ID_MPEG1VIDEO,
- mpeg_mux_init,
- mpeg_mux_write_packet,
- mpeg_mux_end,
-};
-
-static AVOutputFormat mpeg1vcd_mux = {
- "vcd",
- "MPEG1 System format (VCD)",
- "video/mpeg",
- NULL,
- sizeof(MpegMuxContext),
- CODEC_ID_MP2,
- CODEC_ID_MPEG1VIDEO,
- mpeg_mux_init,
- mpeg_mux_write_packet,
- mpeg_mux_end,
-};
-
-static AVOutputFormat mpeg2vob_mux = {
- "vob",
- "MPEG2 PS format (VOB)",
- "video/mpeg",
- "vob",
- sizeof(MpegMuxContext),
- CODEC_ID_MP2,
- CODEC_ID_MPEG1VIDEO,
- mpeg_mux_init,
- mpeg_mux_write_packet,
- mpeg_mux_end,
-};
-
-AVInputFormat mpegps_demux = {
- "mpeg",
- "MPEG PS format",
- sizeof(MpegDemuxContext),
- mpegps_probe,
- mpegps_read_header,
- mpegps_read_packet,
- mpegps_read_close,
- .flags = AVFMT_NOHEADER,
-};
-
-int mpegps_init(void)
-{
- av_register_output_format(&mpeg1system_mux);
- av_register_output_format(&mpeg1vcd_mux);
- av_register_output_format(&mpeg2vob_mux);
- av_register_input_format(&mpegps_demux);
- return 0;
-}
projects / synfig.git / blobdiff