mov.c.svn-base

ffmpeg最新源码

            get_be32(pb); /* horiz resolution */
            get_be32(pb); /* vert resolution */
            get_be32(pb); /* data size, always 0 */
            get_be16(pb); /* frames per samples */

            get_buffer(pb, codec_name, 32); /* codec name, pascal string */
            if (codec_name[0] <= 31) {
                memcpy(st->codec->codec_name, &codec_name[1],codec_name[0]);
                st->codec->codec_name[codec_name[0]] = 0;
            }

            st->codec->bits_per_sample = get_be16(pb); /* depth */
            st->codec->color_table_id = get_be16(pb); /* colortable id */
            dprintf(c->fc, "depth %d, ctab id %d\n",
                   st->codec->bits_per_sample, st->codec->color_table_id);
            /* figure out the palette situation */
            color_depth = st->codec->bits_per_sample & 0x1F;
            color_greyscale = st->codec->bits_per_sample & 0x20;

            /* if the depth is 2, 4, or 8 bpp, file is palettized */
            if ((color_depth == 2) || (color_depth == 4) ||
                (color_depth == 8)) {
                /* for palette traversal */
                unsigned int color_start, color_count, color_end;
                unsigned char r, g, b;

                if (color_greyscale) {
                    int color_index, color_dec;
                    /* compute the greyscale palette */
                    st->codec->bits_per_sample = color_depth;
                    color_count = 1 << color_depth;
                    color_index = 255;
                    color_dec = 256 / (color_count - 1);
                    for (j = 0; j < color_count; j++) {
                        r = g = b = color_index;
                        c->palette_control.palette[j] =
                            (r << 16) | (g << 8) | (b);
                        color_index -= color_dec;
                        if (color_index < 0)
                            color_index = 0;
                    }
                } else if (st->codec->color_table_id) {
                    const uint8_t *color_table;
                    /* if flag bit 3 is set, use the default palette */
                    color_count = 1 << color_depth;
                    if (color_depth == 2)
                        color_table = ff_qt_default_palette_4;
                    else if (color_depth == 4)
                        color_table = ff_qt_default_palette_16;
                    else
                        color_table = ff_qt_default_palette_256;

                    for (j = 0; j < color_count; j++) {
                        r = color_table[j * 4 + 0];
                        g = color_table[j * 4 + 1];
                        b = color_table[j * 4 + 2];
                        c->palette_control.palette[j] =
                            (r << 16) | (g << 8) | (b);
                    }
                } else {
                    /* load the palette from the file */
                    color_start = get_be32(pb);
                    color_count = get_be16(pb);
                    color_end = get_be16(pb);
                    if ((color_start <= 255) &&
                        (color_end <= 255)) {
                        for (j = color_start; j <= color_end; j++) {
                            /* each R, G, or B component is 16 bits;
                             * only use the top 8 bits; skip alpha bytes
                             * up front */
                            get_byte(pb);
                            get_byte(pb);
                            r = get_byte(pb);
                            get_byte(pb);
                            g = get_byte(pb);
                            get_byte(pb);
                            b = get_byte(pb);
                            get_byte(pb);
                            c->palette_control.palette[j] =
                                (r << 16) | (g << 8) | (b);
                        }
                    }
                }
                st->codec->palctrl = &c->palette_control;
                st->codec->palctrl->palette_changed = 1;
            } else
                st->codec->palctrl = NULL;
        } else if(st->codec->codec_type==CODEC_TYPE_AUDIO) {
            int bits_per_sample;
            uint16_t version = get_be16(pb);

            st->codec->codec_id = id;
            get_be16(pb); /* revision level */
            get_be32(pb); /* vendor */

            st->codec->channels = get_be16(pb);             /* channel count */
            dprintf(c->fc, "audio channels %d\n", st->codec->channels);
            st->codec->bits_per_sample = get_be16(pb);      /* sample size */

            sc->audio_cid = get_be16(pb);
            get_be16(pb); /* packet size = 0 */

            st->codec->sample_rate = ((get_be32(pb) >> 16));

            switch (st->codec->codec_id) {
            case CODEC_ID_PCM_S8:
            case CODEC_ID_PCM_U8:
                if (st->codec->bits_per_sample == 16)
                    st->codec->codec_id = CODEC_ID_PCM_S16BE;
                break;
            case CODEC_ID_PCM_S16LE:
            case CODEC_ID_PCM_S16BE:
                if (st->codec->bits_per_sample == 8)
                    st->codec->codec_id = CODEC_ID_PCM_S8;
                else if (st->codec->bits_per_sample == 24)
                    st->codec->codec_id = CODEC_ID_PCM_S24BE;
                break;
            /* set values for old format before stsd version 1 appeared */
            case CODEC_ID_MACE3:
                sc->samples_per_frame = 6;
                sc->bytes_per_frame = 2*st->codec->channels;
                break;
            case CODEC_ID_MACE6:
                sc->samples_per_frame = 6;
                sc->bytes_per_frame = 1*st->codec->channels;
                break;
            case CODEC_ID_ADPCM_IMA_QT:
                sc->samples_per_frame = 64;
                sc->bytes_per_frame = 34*st->codec->channels;
                break;
            case CODEC_ID_GSM:
                sc->samples_per_frame = 160;
                sc->bytes_per_frame = 33;
                break;
            default:
                break;
            }

            //Read QT version 1 fields. In version 0 these do not exist.
            dprintf(c->fc, "version =%d, isom =%d\n",version,c->isom);
            if(!c->isom) {
                if(version==1) {
                    sc->samples_per_frame = get_be32(pb);
                    get_be32(pb); /* bytes per packet */
                    sc->bytes_per_frame = get_be32(pb);
                    get_be32(pb); /* bytes per sample */
                } else if(version==2) {
                    get_be32(pb); /* sizeof struct only */
                    st->codec->sample_rate = av_int2dbl(get_be64(pb)); /* float 64 */
                    st->codec->channels = get_be32(pb);
                    get_be32(pb); /* always 0x7F000000 */
                    get_be32(pb); /* bits per channel if sound is uncompressed */
                    get_be32(pb); /* lcpm format specific flag */
                    get_be32(pb); /* bytes per audio packet if constant */
                    get_be32(pb); /* lpcm frames per audio packet if constant */
                }
            }

            bits_per_sample = av_get_bits_per_sample(st->codec->codec_id);
            if (bits_per_sample) {
                st->codec->bits_per_sample = bits_per_sample;
                sc->sample_size = (bits_per_sample >> 3) * st->codec->channels;
            }
        } else if(st->codec->codec_type==CODEC_TYPE_SUBTITLE){
            st->codec->codec_id= id;
        } else {
            /* other codec type, just skip (rtp, mp4s, tmcd ...) */
            url_fskip(pb, size - (url_ftell(pb) - start_pos));
        }
        /* this will read extra atoms at the end (wave, alac, damr, avcC, SMI ...) */
        a.size = size - (url_ftell(pb) - start_pos);
        if (a.size > 8) {
            if (mov_read_default(c, pb, a) < 0)
                return -1;
        } else if (a.size > 0)
            url_fskip(pb, a.size);
    }

    if(st->codec->codec_type==CODEC_TYPE_AUDIO && st->codec->sample_rate==0 && sc->time_scale>1)
        st->codec->sample_rate= sc->time_scale;

    /* special codec parameters handling */
    switch (st->codec->codec_id) {
#ifdef CONFIG_DV_DEMUXER
    case CODEC_ID_DVAUDIO:
        c->dv_fctx = av_alloc_format_context();
        c->dv_demux = dv_init_demux(c->dv_fctx);
        if (!c->dv_demux) {
            av_log(c->fc, AV_LOG_ERROR, "dv demux context init error\n");
            return -1;
        }
        sc->dv_audio_container = 1;
        st->codec->codec_id = CODEC_ID_PCM_S16LE;
        break;
#endif
    /* no ifdef since parameters are always those */
    case CODEC_ID_AMR_WB:
        st->codec->sample_rate= 16000;
        st->codec->channels= 1; /* really needed */
        break;
    case CODEC_ID_QCELP:
    case CODEC_ID_AMR_NB:
        st->codec->frame_size= sc->samples_per_frame;
        st->codec->sample_rate= 8000;
        st->codec->channels= 1; /* really needed */
        break;
    case CODEC_ID_MP2:
    case CODEC_ID_MP3:
        st->codec->codec_type = CODEC_TYPE_AUDIO; /* force type after stsd for m1a hdlr */
        st->need_parsing = AVSTREAM_PARSE_FULL;
        break;
    case CODEC_ID_GSM:
    case CODEC_ID_ADPCM_MS:
    case CODEC_ID_ADPCM_IMA_WAV:
        st->codec->block_align = sc->bytes_per_frame;
        break;
    case CODEC_ID_ALAC:
        if (st->codec->extradata_size == 36)
            st->codec->frame_size = AV_RB32((st->codec->extradata+12));
        break;
    default:
        break;
    }

    return 0;
}

static int mov_read_stsc(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
{
    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
    MOVStreamContext *sc = st->priv_data;
    unsigned int i, entries;

    get_byte(pb); /* version */
    get_be24(pb); /* flags */

    entries = get_be32(pb);

    if(entries >= UINT_MAX / sizeof(MOV_stsc_t))
        return -1;

    dprintf(c->fc, "track[%i].stsc.entries = %i\n", c->fc->nb_streams-1, entries);

    sc->sample_to_chunk_sz = entries;
    sc->sample_to_chunk = av_malloc(entries * sizeof(MOV_stsc_t));
    if (!sc->sample_to_chunk)
        return -1;
    for(i=0; i<entries; i++) {
        sc->sample_to_chunk[i].first = get_be32(pb);
        sc->sample_to_chunk[i].count = get_be32(pb);
        sc->sample_to_chunk[i].id = get_be32(pb);
    }
    return 0;
}

static int mov_read_stss(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
{
    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
    MOVStreamContext *sc = st->priv_data;
    unsigned int i, entries;

    get_byte(pb); /* version */
    get_be24(pb); /* flags */

    entries = get_be32(pb);

    if(entries >= UINT_MAX / sizeof(int))
        return -1;

    sc->keyframe_count = entries;

    dprintf(c->fc, "keyframe_count = %d\n", sc->keyframe_count);

    sc->keyframes = av_malloc(entries * sizeof(int));
    if (!sc->keyframes)
        return -1;
    for(i=0; i<entries; i++) {
        sc->keyframes[i] = get_be32(pb);
        //dprintf(c->fc, "keyframes[]=%d\n", sc->keyframes[i]);
    }
    return 0;
}

static int mov_read_stsz(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
{
    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
    MOVStreamContext *sc = st->priv_data;
    unsigned int i, entries, sample_size;

    get_byte(pb); /* version */
    get_be24(pb); /* flags */

    sample_size = get_be32(pb);
    if (!sc->sample_size) /* do not overwrite value computed in stsd */
        sc->sample_size = sample_size;
    entries = get_be32(pb);
    if(entries >= UINT_MAX / sizeof(int))
        return -1;

    sc->sample_count = entries;
    if (sample_size)
        return 0;

    dprintf(c->fc, "sample_size = %d sample_count = %d\n", sc->sample_size, sc->sample_count);

    sc->sample_sizes = av_malloc(entries * sizeof(int));
    if (!sc->sample_sizes)
        return -1;
    for(i=0; i<entries; i++)
        sc->sample_sizes[i] = get_be32(pb);
    return 0;
}

static int mov_read_stts(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
{
    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
    MOVStreamContext *sc = st->priv_data;
    unsigned int i, entries;
    int64_t duration=0;
    int64_t total_sample_count=0;

    get_byte(pb); /* version */
    get_be24(pb); /* flags */
    entries = get_be32(pb);
    if(entries >= UINT_MAX / sizeof(MOV_stts_t))
        return -1;

    sc->stts_count = entries;
    sc->stts_data = av_malloc(entries * sizeof(MOV_stts_t));
    if (!sc->stts_data)
        return -1;
    dprintf(c->fc, "track[%i].stts.entries = %i\n", c->fc->nb_streams-1, entries);

    sc->time_rate=0;

    for(i=0; i<entries; i++) {
        int sample_duration;
        int sample_count;

        sample_count=get_be32(pb);
        sample_duration = get_be32(pb);
        sc->stts_data[i].count= sample_count;
        sc->stts_data[i].duration= sample_duration;

        sc->time_rate= ff_gcd(sc->time_rate, sample_duration);

        dprintf(c->fc, "sample_count=%d, sample_duration=%d\n",sample_count,sample_duration);

        duration+=(int64_t)sample_duration*sample_count;
        total_sample_count+=sample_count;
    }

    st->nb_frames= total_sample_count;
    if(duration)
        st->duration= duration;
    return 0;
}

static int mov_read_ctts(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
{
    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
    MOVStreamContext *sc = st->priv_data;
    unsigned int i, entries;

    get_byte(pb); /* version */
    get_be24(pb); /* flags */
    entries = get_be32(pb);
    if(entries >= UINT_MAX / sizeof(MOV_stts_t))
        return -1;

    sc->ctts_count = entries;
    sc->ctts_data = av_malloc(entries * sizeof(MOV_stts_t));
    if (!sc->ctts_data)