Initial revision

Originally committed as revision 5 to svn://svn.ffmpeg.org/ffmpeg/trunk

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,
+};