PeerStreamer

/*

 * Sierra VMD Format Demuxer

 * Copyright (c) 2004 The ffmpeg Project

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg 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.

 *

 * FFmpeg 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 FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

/**

 * @file

 * Sierra VMD file demuxer

 * by Vladimir "VAG" Gneushev (vagsoft at mail.ru)

 * for more information on the Sierra VMD file format, visit:

 *   http://www.pcisys.net/~melanson/codecs/

 */

#include "libavutil/intreadwrite.h"

#include "avformat.h"

#define VMD_HEADER_SIZE 0x0330

#define BYTES_PER_FRAME_RECORD 16

typedef struct {

  int stream_index;

  int64_t frame_offset;

  unsigned int frame_size;

  int64_t pts;

  int keyframe;

  unsigned char frame_record[BYTES_PER_FRAME_RECORD];

} vmd_frame;

typedef struct VmdDemuxContext {

    int video_stream_index;

    int audio_stream_index;

    unsigned int frame_count;

    unsigned int frames_per_block;

    vmd_frame *frame_table;

    unsigned int current_frame;

    int is_indeo3;

    int sample_rate;

    int64_t audio_sample_counter;

    int skiphdr;

    unsigned char vmd_header[VMD_HEADER_SIZE];

} VmdDemuxContext;

static int vmd_probe(AVProbeData *p)

{

    int w, h;

    if (p->buf_size < 16)

        return 0;

    /* check if the first 2 bytes of the file contain the appropriate size

     * of a VMD header chunk */

    if (AV_RL16(&p->buf[0]) != VMD_HEADER_SIZE - 2)

        return 0;

    w = AV_RL16(&p->buf[12]);

    h = AV_RL16(&p->buf[14]);

    if (!w || w > 2048 || !h || h > 2048)

        return 0;

    /* only return half certainty since this check is a bit sketchy */

    return AVPROBE_SCORE_MAX / 2;

}

static int vmd_read_header(AVFormatContext *s,

                           AVFormatParameters *ap)

{

    VmdDemuxContext *vmd = s->priv_data;

    AVIOContext *pb = s->pb;

    AVStream *st = NULL, *vst;

    unsigned int toc_offset;

    unsigned char *raw_frame_table;

    int raw_frame_table_size;

    int64_t current_offset;

    int i, j;

    unsigned int total_frames;

    int64_t current_audio_pts = 0;

    unsigned char chunk[BYTES_PER_FRAME_RECORD];

    int num, den;

    int sound_buffers;

    /* fetch the main header, including the 2 header length bytes */

    avio_seek(pb, 0, SEEK_SET);

    if (avio_read(pb, vmd->vmd_header, VMD_HEADER_SIZE) != VMD_HEADER_SIZE)

        return AVERROR(EIO);

    if(vmd->vmd_header[16] == 'i' && vmd->vmd_header[17] == 'v' && vmd->vmd_header[18] == '3')

        vmd->is_indeo3 = 1;

    else

        vmd->is_indeo3 = 0;

    /* start up the decoders */

    vst = av_new_stream(s, 0);

    if (!vst)

        return AVERROR(ENOMEM);

    av_set_pts_info(vst, 33, 1, 10);

    vmd->video_stream_index = vst->index;

    vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;

    vst->codec->codec_id = vmd->is_indeo3 ? CODEC_ID_INDEO3 : CODEC_ID_VMDVIDEO;

    vst->codec->codec_tag = 0;  /* no fourcc */

    vst->codec->width = AV_RL16(&vmd->vmd_header[12]);

    vst->codec->height = AV_RL16(&vmd->vmd_header[14]);

    if(vmd->is_indeo3 && vst->codec->width > 320){

        vst->codec->width >>= 1;

        vst->codec->height >>= 1;

    }

    vst->codec->extradata_size = VMD_HEADER_SIZE;

    vst->codec->extradata = av_mallocz(VMD_HEADER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);

    memcpy(vst->codec->extradata, vmd->vmd_header, VMD_HEADER_SIZE);

    /* if sample rate is 0, assume no audio */

    vmd->sample_rate = AV_RL16(&vmd->vmd_header[804]);

    if (vmd->sample_rate) {

        st = av_new_stream(s, 0);

        if (!st)

            return AVERROR(ENOMEM);

        vmd->audio_stream_index = st->index;

        st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

        st->codec->codec_id = CODEC_ID_VMDAUDIO;

        st->codec->codec_tag = 0;  /* no fourcc */

        st->codec->channels = (vmd->vmd_header[811] & 0x80) ? 2 : 1;

        st->codec->sample_rate = vmd->sample_rate;

        st->codec->block_align = AV_RL16(&vmd->vmd_header[806]);

        if (st->codec->block_align & 0x8000) {

            st->codec->bits_per_coded_sample = 16;

            st->codec->block_align = -(st->codec->block_align - 0x10000);

        } else {

            st->codec->bits_per_coded_sample = 8;

        }

        st->codec->bit_rate = st->codec->sample_rate *

            st->codec->bits_per_coded_sample * st->codec->channels;

        /* calculate pts */

        num = st->codec->block_align;

        den = st->codec->sample_rate * st->codec->channels;

        av_reduce(&den, &num, den, num, (1UL<<31)-1);

        av_set_pts_info(vst, 33, num, den);

        av_set_pts_info(st, 33, num, den);

    }

    toc_offset = AV_RL32(&vmd->vmd_header[812]);

    vmd->frame_count = AV_RL16(&vmd->vmd_header[6]);

    vmd->frames_per_block = AV_RL16(&vmd->vmd_header[18]);

    avio_seek(pb, toc_offset, SEEK_SET);

    raw_frame_table = NULL;

    vmd->frame_table = NULL;

    sound_buffers = AV_RL16(&vmd->vmd_header[808]);

    raw_frame_table_size = vmd->frame_count * 6;

    if(vmd->frame_count * vmd->frames_per_block >= UINT_MAX / sizeof(vmd_frame) - sound_buffers){

        av_log(s, AV_LOG_ERROR, "vmd->frame_count * vmd->frames_per_block too large\n");

        return -1;

    }

    raw_frame_table = av_malloc(raw_frame_table_size);

    vmd->frame_table = av_malloc((vmd->frame_count * vmd->frames_per_block + sound_buffers) * sizeof(vmd_frame));

    if (!raw_frame_table || !vmd->frame_table) {

        av_free(raw_frame_table);

        av_free(vmd->frame_table);

        return AVERROR(ENOMEM);

    }

    if (avio_read(pb, raw_frame_table, raw_frame_table_size) !=

        raw_frame_table_size) {

        av_free(raw_frame_table);

        av_free(vmd->frame_table);

        return AVERROR(EIO);

    }

    total_frames = 0;

    for (i = 0; i < vmd->frame_count; i++) {

        current_offset = AV_RL32(&raw_frame_table[6 * i + 2]);

        /* handle each entry in index block */

        for (j = 0; j < vmd->frames_per_block; j++) {

            int type;

            uint32_t size;

            avio_read(pb, chunk, BYTES_PER_FRAME_RECORD);

            type = chunk[0];

            size = AV_RL32(&chunk[2]);

            if(!size && type != 1)

                continue;

            switch(type) {

            case 1: /* Audio Chunk */

                if (!st) break;

                /* first audio chunk contains several audio buffers */

                vmd->frame_table[total_frames].frame_offset = current_offset;

                vmd->frame_table[total_frames].stream_index = vmd->audio_stream_index;

                vmd->frame_table[total_frames].frame_size = size;

                memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);

                vmd->frame_table[total_frames].pts = current_audio_pts;

                total_frames++;

                if(!current_audio_pts)

                    current_audio_pts += sound_buffers;

                else

                    current_audio_pts++;

                break;

            case 2: /* Video Chunk */

                vmd->frame_table[total_frames].frame_offset = current_offset;

                vmd->frame_table[total_frames].stream_index = vmd->video_stream_index;

                vmd->frame_table[total_frames].frame_size = size;

                memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);

                vmd->frame_table[total_frames].pts = i;

                total_frames++;

                break;

            }

            current_offset += size;

        }

    }

    av_free(raw_frame_table);

    vmd->current_frame = 0;

    vmd->frame_count = total_frames;

    return 0;

}

static int vmd_read_packet(AVFormatContext *s,

                           AVPacket *pkt)

{

    VmdDemuxContext *vmd = s->priv_data;

    AVIOContext *pb = s->pb;

    int ret = 0;

    vmd_frame *frame;

    if (vmd->current_frame >= vmd->frame_count)

        return AVERROR(EIO);

    frame = &vmd->frame_table[vmd->current_frame];

    /* position the stream (will probably be there already) */

    avio_seek(pb, frame->frame_offset, SEEK_SET);

    if (av_new_packet(pkt, frame->frame_size + BYTES_PER_FRAME_RECORD))

        return AVERROR(ENOMEM);

    pkt->pos= avio_tell(pb);

    memcpy(pkt->data, frame->frame_record, BYTES_PER_FRAME_RECORD);

    if(vmd->is_indeo3)

        ret = avio_read(pb, pkt->data, frame->frame_size);

    else

        ret = avio_read(pb, pkt->data + BYTES_PER_FRAME_RECORD,

            frame->frame_size);

    if (ret != frame->frame_size) {

        av_free_packet(pkt);

        ret = AVERROR(EIO);

    }

    pkt->stream_index = frame->stream_index;

    pkt->pts = frame->pts;

    av_log(s, AV_LOG_DEBUG, " dispatching %s frame with %d bytes and pts %"PRId64"\n",

            (frame->frame_record[0] == 0x02) ? "video" : "audio",

            frame->frame_size + BYTES_PER_FRAME_RECORD,

            pkt->pts);

    vmd->current_frame++;

    return ret;

}

static int vmd_read_close(AVFormatContext *s)

{

    VmdDemuxContext *vmd = s->priv_data;

    av_free(vmd->frame_table);

    return 0;

}

AVInputFormat ff_vmd_demuxer = {

    "vmd",

    NULL_IF_CONFIG_SMALL("Sierra VMD format"),

    sizeof(VmdDemuxContext),

    vmd_probe,

    vmd_read_header,

    vmd_read_packet,

    vmd_read_close,

};