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-rw-r--r--libav/mpeg.c663
1 files changed, 663 insertions, 0 deletions
diff --git a/libav/mpeg.c b/libav/mpeg.c
new file mode 100644
index 0000000000..86e3af6184
--- /dev/null
+++ b/libav/mpeg.c
@@ -0,0 +1,663 @@
+/*
+ * Output a MPEG1 multiplexed video/audio stream
+ * Copyright (c) 2000 Gerard Lantau.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/time.h>
+
+#include "avformat.h"
+
+#define MAX_PAYLOAD_SIZE 4096
+#define NB_STREAMS 2
+
+typedef struct {
+ UINT8 buffer[MAX_PAYLOAD_SIZE];
+ int buffer_ptr;
+ UINT8 id;
+ int max_buffer_size; /* in bytes */
+ int packet_number;
+ float pts;
+ INT64 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;
+} MpegMuxContext;
+
+#define PACK_START_CODE ((unsigned int)0x000001ba)
+#define SYSTEM_HEADER_START_CODE ((unsigned int)0x000001bb)
+#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
+
+static int put_pack_header(AVFormatContext *ctx,
+ UINT8 *buf, long long timestamp)
+{
+ MpegMuxContext *s = ctx->priv_data;
+ PutBitContext pb;
+
+ init_put_bits(&pb, buf, 128, NULL, NULL);
+
+ put_bits(&pb, 32, PACK_START_CODE);
+ put_bits(&pb, 4, 0x2);
+ put_bits(&pb, 3, (timestamp >> 30) & 0x07);
+ put_bits(&pb, 1, 1);
+ put_bits(&pb, 15, (timestamp >> 15) & 0x7fff);
+ put_bits(&pb, 1, 1);
+ put_bits(&pb, 15, (timestamp) & 0x7fff);
+ put_bits(&pb, 1, 1);
+ put_bits(&pb, 1, 1);
+ put_bits(&pb, 22, s->mux_rate);
+ put_bits(&pb, 1, 1);
+
+ flush_put_bits(&pb);
+ return pb.buf_ptr - pb.buf;
+}
+
+static int put_system_header(AVFormatContext *ctx, UINT8 *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 = pb.buf_ptr - 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;
+ int bitrate, i, mpa_id, mpv_id, ac3_id;
+ AVStream *st;
+ StreamInfo *stream;
+
+ s = malloc(sizeof(MpegMuxContext));
+ if (!s)
+ return -1;
+ memset(s, 0, sizeof(MpegMuxContext));
+ ctx->priv_data = s;
+ s->packet_number = 0;
+
+ /* XXX: hardcoded */
+ 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;
+ }
+ }
+
+ /* 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);
+ /* every 2 seconds */
+ s->pack_header_freq = 2 * bitrate / s->packet_size / 8;
+ /* every 10 seconds */
+ 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->pts = 0;
+ stream->start_pts = -1;
+ }
+ return 0;
+ fail:
+ for(i=0;i<ctx->nb_streams;i++) {
+ free(ctx->streams[i]->priv_data);
+ }
+ free(s);
+ 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 *buf_ptr;
+ int size, payload_size, startcode, id, len, stuffing_size, i;
+ INT64 timestamp;
+ UINT8 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 */
+ payload_size = s->packet_size - (size + 6 + 5);
+ 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 + 5);
+ /* stuffing */
+ for(i=0;i<stuffing_size;i++)
+ put_byte(&ctx->pb, 0xff);
+
+ /* presentation time stamp */
+ put_byte(&ctx->pb,
+ (0x02 << 4) |
+ (((timestamp >> 30) & 0x07) << 1) |
+ 1);
+ put_be16(&ctx->pb, (((timestamp >> 15) & 0x7fff) << 1) | 1);
+ put_be16(&ctx->pb, (((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, UINT8 *buf, int size)
+{
+ 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 = stream->pts * 90000.0;
+ 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 = stream->pts * 90000.0;
+ flush_packet(ctx, stream_index);
+ }
+ }
+
+ if (st->codec.codec_type == CODEC_TYPE_AUDIO) {
+ stream->pts += (float)st->codec.frame_size / st->codec.sample_rate;
+ } else {
+ stream->pts += FRAME_RATE_BASE / (float)st->codec.frame_rate;
+ }
+ 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);
+ }
+
+ /* write the end header */
+ put_be32(&ctx->pb, ISO_11172_END_CODE);
+ put_flush_packet(&ctx->pb);
+ return 0;
+}
+
+/*********************************************/
+/* demux code */
+
+#define MAX_SYNC_SIZE 100000
+
+typedef struct MpegDemuxContext {
+ int header_state;
+ int mux_rate; /* 50 byte/s unit */
+} MpegDemuxContext;
+
+static int find_start_code(ByteIOContext *pb, int *size_ptr,
+ UINT32 *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 mpeg_mux_read_header(AVFormatContext *s,
+ AVFormatParameters *ap)
+{
+ MpegDemuxContext *m;
+ int size, startcode, c, rate_bound, audio_bound, video_bound, mux_rate, val;
+ int codec_id, n, i, type;
+ AVStream *st;
+
+ m = av_mallocz(sizeof(MpegDemuxContext));
+ if (!m)
+ return -ENOMEM;
+ s->priv_data = m;
+
+ /* search first pack header */
+ m->header_state = 0xff;
+ size = MAX_SYNC_SIZE;
+ for(;;) {
+ while (size > 0) {
+ startcode = find_start_code(&s->pb, &size, &m->header_state);
+ if (startcode == PACK_START_CODE)
+ goto found;
+ }
+ return -ENODATA;
+ found:
+ /* search system header just after pack header */
+ /* parse pack header */
+ get_byte(&s->pb); /* ts1 */
+ get_be16(&s->pb); /* ts2 */
+ get_be16(&s->pb); /* ts3 */
+
+ mux_rate = get_byte(&s->pb) << 16;
+ mux_rate |= get_byte(&s->pb) << 8;
+ mux_rate |= get_byte(&s->pb);
+ mux_rate &= (1 << 22) - 1;
+ m->mux_rate = mux_rate;
+
+ startcode = find_start_code(&s->pb, &size, &m->header_state);
+ if (startcode == SYSTEM_HEADER_START_CODE)
+ break;
+ }
+ size = get_be16(&s->pb);
+ rate_bound = get_byte(&s->pb) << 16;
+ rate_bound |= get_byte(&s->pb) << 8;
+ rate_bound |= get_byte(&s->pb);
+ rate_bound = (rate_bound >> 1) & ((1 << 22) - 1);
+ audio_bound = get_byte(&s->pb) >> 2;
+ video_bound = get_byte(&s->pb) & 0x1f;
+ get_byte(&s->pb); /* reserved byte */
+#if 0
+ printf("mux_rate=%d kbit/s\n", (m->mux_rate * 50 * 8) / 1000);
+ printf("rate_bound=%d\n", rate_bound);
+ printf("audio_bound=%d\n", audio_bound);
+ printf("video_bound=%d\n", video_bound);
+#endif
+ size -= 6;
+ s->nb_streams = 0;
+ while (size > 0) {
+ c = get_byte(&s->pb);
+ size--;
+ if ((c & 0x80) == 0)
+ break;
+ val = get_be16(&s->pb);
+ size -= 2;
+ if (c >= 0xc0 && c <= 0xdf) {
+ /* mpeg audio stream */
+ type = CODEC_TYPE_AUDIO;
+ codec_id = CODEC_ID_MP2;
+ n = 1;
+ c = c | 0x100;
+ } else if (c >= 0xe0 && c <= 0xef) {
+ type = CODEC_TYPE_VIDEO;
+ codec_id = CODEC_ID_MPEG1VIDEO;
+ n = 1;
+ c = c | 0x100;
+ } else if (c == 0xb8) {
+ /* all audio streams */
+ /* XXX: hack for DVD: we force AC3, although we do not
+ know that this codec will be used */
+ type = CODEC_TYPE_AUDIO;
+ codec_id = CODEC_ID_AC3;
+ n = audio_bound;
+ c = 0x80;
+ /* c = 0x1c0; */
+ } else if (c == 0xb9) {
+ /* all video streams */
+ type = CODEC_TYPE_VIDEO;
+ codec_id = CODEC_ID_MPEG1VIDEO;
+ n = video_bound;
+ c = 0x1e0;
+ } else {
+ type = 0;
+ codec_id = 0;
+ n = 0;
+ }
+
+ for(i=0;i<n;i++) {
+ st = av_mallocz(sizeof(AVStream));
+ if (!st)
+ return -ENOMEM;
+ s->streams[s->nb_streams++] = st;
+ st->id = c + i;
+ st->codec.codec_type = type;
+ st->codec.codec_id = codec_id;
+ }
+ }
+
+ return 0;
+}
+
+static INT64 get_pts(ByteIOContext *pb, int c)
+{
+ INT64 pts;
+ int val;
+
+ if (c < 0)
+ c = get_byte(pb);
+ pts = (INT64)((c >> 1) & 0x07) << 30;
+ val = get_be16(pb);
+ pts |= (INT64)(val >> 1) << 15;
+ val = get_be16(pb);
+ pts |= (INT64)(val >> 1);
+ return pts;
+}
+
+static int mpeg_mux_read_packet(AVFormatContext *s,
+ AVPacket *pkt)
+{
+ MpegDemuxContext *m = s->priv_data;
+ AVStream *st;
+ int len, size, startcode, i, c, flags, header_len;
+ INT64 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 = 0;
+ dts = 0;
+ /* 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;
+ dts = pts;
+ } 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) == 0x40) {
+ pts = get_pts(&s->pb, -1);
+ dts = pts;
+ 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;
+ }
+ /* skip packet */
+ url_fskip(&s->pb, len);
+ goto redo;
+ found:
+ av_new_packet(pkt, len);
+ get_buffer(&s->pb, pkt->data, pkt->size);
+ pkt->pts = pts;
+ pkt->stream_index = i;
+ return 0;
+}
+
+static int mpeg_mux_read_close(AVFormatContext *s)
+{
+ MpegDemuxContext *m = s->priv_data;
+ free(m);
+ return 0;
+}
+
+AVFormat mpeg_mux_format = {
+ "mpeg",
+ "MPEG multiplex format",
+ "video/x-mpeg",
+ "mpg,mpeg,vob",
+ CODEC_ID_MP2,
+ CODEC_ID_MPEG1VIDEO,
+ mpeg_mux_init,
+ mpeg_mux_write_packet,
+ mpeg_mux_end,
+
+ mpeg_mux_read_header,
+ mpeg_mux_read_packet,
+ mpeg_mux_read_close,
+};
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