/* * Sierra VMD Format Demuxer * Copyright (c) 2004 The ffmpeg Project * * 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 *//** * @file sierravmd.c * 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 "avformat.h"#define VMD_HEADER_SIZE 0x0330#define BYTES_PER_FRAME_RECORD 16typedef struct {  int stream_index;  offset_t frame_offset;  unsigned int frame_size;  int64_t pts;  int keyframe;  unsigned char frame_record[BYTES_PER_FRAME_RECORD];} vmd_frame_t;typedef struct VmdDemuxContext {    int video_stream_index;    int audio_stream_index;    unsigned int audio_type;    unsigned int audio_samplerate;    unsigned int audio_bits;    unsigned int audio_channels;    unsigned int frame_count;    vmd_frame_t *frame_table;    unsigned int current_frame;    int sample_rate;    int64_t audio_sample_counter;    int audio_frame_divisor;    int audio_block_align;    unsigned char vmd_header[VMD_HEADER_SIZE];} VmdDemuxContext;static int vmd_probe(AVProbeData *p){    if (p->buf_size < 2)        return 0;    /* check if the first 2 bytes of the file contain the appropriate size     * of a VMD header chunk */    if (LE_16(&p->buf[0]) != VMD_HEADER_SIZE - 2)        return 0;    /* only return half certainty since this check is a bit sketchy */    return AVPROBE_SCORE_MAX / 2;}/* This is a support function to determine the duration, in sample * frames, of a particular audio chunk, taking into account silent * encodings. */static int vmd_calculate_audio_duration(unsigned char *audio_chunk,    int audio_chunk_size, int block_align){    unsigned char *p = audio_chunk + 16;    unsigned char *p_end = audio_chunk + audio_chunk_size;    int total_samples = 0;    unsigned int sound_flags;    if (audio_chunk_size < 16)        return 0;    sound_flags = LE_32(p);    p += 4;    while (p < p_end) {        total_samples += block_align;        if ((sound_flags & 0x01) == 0)            p += block_align;        sound_flags >>= 1;    }    return total_samples;}static int vmd_read_header(AVFormatContext *s,                           AVFormatParameters *ap){    VmdDemuxContext *vmd = (VmdDemuxContext *)s->priv_data;    ByteIOContext *pb = &s->pb;    AVStream *st;    unsigned int toc_offset;    unsigned char *raw_frame_table;    int raw_frame_table_size;    unsigned char *current_frame_record;    offset_t current_offset;    int i;    unsigned int total_frames;    int64_t video_pts_inc;    int64_t current_video_pts = 0;    /* fetch the main header, including the 2 header length bytes */    url_fseek(pb, 0, SEEK_SET);    if (get_buffer(pb, vmd->vmd_header, VMD_HEADER_SIZE) != VMD_HEADER_SIZE)        return -EIO;    vmd->audio_sample_counter = 0;    vmd->audio_frame_divisor = 1;    vmd->audio_block_align = 1;    /* start up the decoders */    st = av_new_stream(s, 0);    if (!st)        return AVERROR_NOMEM;    vmd->video_stream_index = st->index;    st->codec.codec_type = CODEC_TYPE_VIDEO;    st->codec.codec_id = CODEC_ID_VMDVIDEO;    st->codec.codec_tag = 0;  /* no fourcc */    st->codec.width = LE_16(&vmd->vmd_header[12]);    st->codec.height = LE_16(&vmd->vmd_header[14]);    st->codec.extradata_size = VMD_HEADER_SIZE;    st->codec.extradata = av_malloc(VMD_HEADER_SIZE);    memcpy(st->codec.extradata, vmd->vmd_header, VMD_HEADER_SIZE);    /* if sample rate is 0, assume no audio */    vmd->sample_rate = LE_16(&vmd->vmd_header[804]);    if (vmd->sample_rate) {        st = av_new_stream(s, 0);        if (!st)            return AVERROR_NOMEM;        vmd->audio_stream_index = st->index;        st->codec.codec_type = CODEC_TYPE_AUDIO;        st->codec.codec_id = CODEC_ID_VMDAUDIO;        st->codec.codec_tag = 0;  /* no codec tag */        st->codec.channels = (vmd->vmd_header[811] & 0x80) ? 2 : 1;        st->codec.sample_rate = vmd->sample_rate;        st->codec.block_align = vmd->audio_block_align =             LE_16(&vmd->vmd_header[806]);        if (st->codec.block_align & 0x8000) {            st->codec.bits_per_sample = 16;            st->codec.block_align = -(st->codec.block_align - 0x10000);        } else            st->codec.bits_per_sample = 16;//            st->codec.bits_per_sample = 8;        st->codec.bit_rate = st->codec.sample_rate *             st->codec.bits_per_sample * st->codec.channels;        /* for calculating pts */        vmd->audio_frame_divisor = st->codec.bits_per_sample / 8 /             st->codec.channels;        video_pts_inc = 90000;        video_pts_inc *= st->codec.block_align;        video_pts_inc /= st->codec.sample_rate;    } else {        /* if no audio, assume 10 frames/second */        video_pts_inc = 90000 / 10;    }    /* skip over the offset table and load the table of contents; don't      * care about the offset table since demuxer will calculate those      * independently */    toc_offset = LE_32(&vmd->vmd_header[812]);    vmd->frame_count = LE_16(&vmd->vmd_header[6]);    url_fseek(pb, toc_offset + vmd->frame_count * 6, SEEK_SET);    /* each on-disk VMD frame has an audio part and a video part; demuxer     * accounts them separately */    vmd->frame_count *= 2;    raw_frame_table = NULL;    vmd->frame_table = NULL;    raw_frame_table_size = vmd->frame_count * BYTES_PER_FRAME_RECORD;    raw_frame_table = av_malloc(raw_frame_table_size);    vmd->frame_table = av_malloc(vmd->frame_count * sizeof(vmd_frame_t));    if (!raw_frame_table || !vmd->frame_table) {        av_free(raw_frame_table);        av_free(vmd->frame_table);        return AVERROR_NOMEM;    }    if (get_buffer(pb, raw_frame_table, raw_frame_table_size) !=         raw_frame_table_size) {        av_free(raw_frame_table);        av_free(vmd->frame_table);        return -EIO;    }    current_offset = LE_32(&vmd->vmd_header[20]);    current_frame_record = raw_frame_table;    total_frames = vmd->frame_count;    i = 0;    while (total_frames--) {        /* if the frame size is 0, do not count the frame and bring the         * total frame count down */        vmd->frame_table[i].frame_size = LE_32(&current_frame_record[2]);        /* this logic is present so that 0-length audio chunks are not         * accounted */        if (!vmd->frame_table[i].frame_size) {            vmd->frame_count--;  /* one less frame to count */            current_frame_record += BYTES_PER_FRAME_RECORD;            continue;        }        if (current_frame_record[0] == 0x02)            vmd->frame_table[i].stream_index = vmd->video_stream_index;        else            vmd->frame_table[i].stream_index = vmd->audio_stream_index;        vmd->frame_table[i].frame_offset = current_offset;        current_offset += vmd->frame_table[i].frame_size;        memcpy(vmd->frame_table[i].frame_record, current_frame_record,            BYTES_PER_FRAME_RECORD);        /* figure out the pts for this frame */        if (current_frame_record[0] == 0x02) {            vmd->frame_table[i].pts = current_video_pts;            current_video_pts += video_pts_inc;        } else if (current_frame_record[0] == 0x01) {            /* figure out the pts during the dispatch phase */            vmd->frame_table[i].pts = 0;        }        current_frame_record += BYTES_PER_FRAME_RECORD;        i++;    }    av_free(raw_frame_table);    /* set the pts reference at 1 pts = 1/90000 sec */    s->pts_num = 1;    s->pts_den = 90000;    vmd->current_frame = 0;    return 0;}static int vmd_read_packet(AVFormatContext *s,                           AVPacket *pkt){    VmdDemuxContext *vmd = (VmdDemuxContext *)s->priv_data;    ByteIOContext *pb = &s->pb;    int ret = 0;    vmd_frame_t *frame;    if (vmd->current_frame >= vmd->frame_count)        return -EIO;    frame = &vmd->frame_table[vmd->current_frame];    /* position the stream (will probably be there already) */    url_fseek(pb, frame->frame_offset, SEEK_SET);    if (av_new_packet(pkt, frame->frame_size + BYTES_PER_FRAME_RECORD))        return AVERROR_NOMEM;    memcpy(pkt->data, frame->frame_record, BYTES_PER_FRAME_RECORD);    ret = get_buffer(pb, pkt->data + BYTES_PER_FRAME_RECORD,         frame->frame_size);    if (ret != frame->frame_size) {        av_free_packet(pkt);        ret = -EIO;    }    pkt->stream_index = frame->stream_index;    if (frame->frame_record[0] == 0x02)        pkt->pts = frame->pts;    else {        pkt->pts = vmd->audio_sample_counter;        pkt->pts *= 90000;        pkt->pts /= vmd->sample_rate;//        pkt->pts /= vmd->audio_frame_divisor;        vmd->audio_sample_counter += vmd_calculate_audio_duration(            pkt->data, pkt->size, vmd->audio_block_align);    }printf (" dispatching %s frame with %d bytes and pts %lld (%0.1f sec)\n",  (frame->frame_record[0] == 0x02) ? "video" : "audio",  frame->frame_size + BYTES_PER_FRAME_RECORD,  pkt->pts, (float)(pkt->pts / 90000.0));    vmd->current_frame++;    return ret;}static int vmd_read_close(AVFormatContext *s){    VmdDemuxContext *vmd = (VmdDemuxContext *)s->priv_data;    av_free(vmd->frame_table);    return 0;}static AVInputFormat vmd_iformat = {    "vmd",    "Sierra VMD format",    sizeof(VmdDemuxContext),    vmd_probe,    vmd_read_header,    vmd_read_packet,    vmd_read_close,};int vmd_init(void){    av_register_input_format(&vmd_iformat);    return 0;}