C++ AV_RB32函数代码示例

int real_get_rdt_chunk(rtsp_t *rtsp_session, char **buffer, int rdt_rawdata) {

  int n=1;
  uint8_t header[8];
  rmff_pheader_t ph;
  int size;
  int flags1, flags2;
  int unknown1;
  uint32_t ts;
  static uint32_t prev_ts = -1;
  static int prev_stream_number = -1;

  n=rtsp_read_data(rtsp_session, header, 8);
  if (n<8) return 0;
  if (header[0] != 0x24)
  {
    mp_msg(MSGT_STREAM, MSGL_WARN, "realrtsp: rdt chunk not recognized: got 0x%02x\n",
      header[0]);
    return 0;
  }
  /* header[1] is channel, normally 0, ignored */
  size=(header[2]<<8)+header[3];
  flags1=header[4];
  if ((flags1 & 0xc0) != 0x40)
  {
#ifdef LOG
    printf("got flags1: 0x%02x\n",flags1);
#endif
    if(header[6] == 0x06) { // eof packet
      rtsp_read_data(rtsp_session, header, 7); // Skip the rest of the eof packet
      /* Some files have short auxiliary streams, we must ignore eof packets
       * for these streams to avoid premature eof.
       * Now the code declares eof only if the stream with id == 0 gets eof
       * (old code was: eof on the first eof packet received).
       */
      if(flags1 & 0x7c) // ignore eof for streams with id != 0
        return 0;
      mp_msg(MSGT_STREAM, MSGL_INFO, "realrtsp: Stream EOF detected\n");
      return -1;
    }
    header[0]=header[5];
    header[1]=header[6];
    header[2]=header[7];
    n=rtsp_read_data(rtsp_session, header+3, 5);
    if (n<5) return 0;
#ifdef LOG
    printf("ignoring bytes:\n");
    hexdump(header, 8);
#endif
    n=rtsp_read_data(rtsp_session, header+4, 4);
    if (n<4) return 0;
    flags1=header[4];
    size-=9;
  }
  flags2=header[7];
  // header[5..6] == frame number in stream
  unknown1=(header[5]<<16)+(header[6]<<8)+(header[7]);
  n=rtsp_read_data(rtsp_session, header, 6);
  if (n<6) return 0;
  ts=AV_RB32(header);

#ifdef LOG
  printf("ts: %u, size: %u, flags: 0x%02x, unknown values: 0x%06x 0x%02x 0x%02x\n",
          ts, size, flags1, unknown1, header[4], header[5]);
#endif
  size+=2;

  ph.object_version=0;
  ph.length=size;
  ph.stream_number=(flags1>>1)&0x1f;
  ph.timestamp=ts;
  ph.reserved=0;
  if ((flags2&1) == 0 && (prev_ts != ts || prev_stream_number != ph.stream_number))
  {
    prev_ts = ts;
    prev_stream_number = ph.stream_number;
    ph.flags=2;
  }
  else
    ph.flags=0;
  *buffer = xbuffer_ensure_size(*buffer, 12+size);
  if(rdt_rawdata) {
      if (size < 12)
          return 0;
    n=rtsp_read_data(rtsp_session, *buffer, size-12);
    return (n <= 0) ? 0 : n;
  }
  rmff_dump_pheader(&ph, *buffer);
  if (size < 12)
      return 0;
  size-=12;
  n=rtsp_read_data(rtsp_session, (*buffer)+12, size);

  return (n <= 0) ? 0 : n+12;
}

static int ea_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    EaDemuxContext *ea = s->priv_data;
    AVIOContext *pb    = s->pb;
    int partial_packet = 0;
    unsigned int chunk_type, chunk_size;
    int ret = 0, packet_read = 0, key = 0;
    int av_uninit(num_samples);

    while (!packet_read || partial_packet) {
        chunk_type = avio_rl32(pb);
        chunk_size = ea->big_endian ? avio_rb32(pb) : avio_rl32(pb);
        if (chunk_size <= 8)
            return AVERROR_INVALIDDATA;
        chunk_size -= 8;

        switch (chunk_type) {
        /* audio data */
        case ISNh_TAG:
            /* header chunk also contains data; skip over the header portion */
            if (chunk_size < 32)
                return AVERROR_INVALIDDATA;
            avio_skip(pb, 32);
            chunk_size -= 32;
        case ISNd_TAG:
        case SCDl_TAG:
        case SNDC_TAG:
        case SDEN_TAG:
            if (!ea->audio_codec) {
                avio_skip(pb, chunk_size);
                break;
            } else if (ea->audio_codec == AV_CODEC_ID_PCM_S16LE_PLANAR ||
                       ea->audio_codec == AV_CODEC_ID_MP3) {
                num_samples = avio_rl32(pb);
                avio_skip(pb, 8);
                chunk_size -= 12;
            }
            if (partial_packet) {
                avpriv_request_sample(s, "video header followed by audio packet");
                av_free_packet(pkt);
                partial_packet = 0;
            }
            ret = av_get_packet(pb, pkt, chunk_size);
            if (ret < 0)
                return ret;
            pkt->stream_index = ea->audio_stream_index;

            switch (ea->audio_codec) {
            case AV_CODEC_ID_ADPCM_EA:
            case AV_CODEC_ID_ADPCM_EA_R1:
            case AV_CODEC_ID_ADPCM_EA_R2:
            case AV_CODEC_ID_ADPCM_IMA_EA_EACS:
                if (pkt->size >= 4)
                    pkt->duration = AV_RL32(pkt->data);
                break;
            case AV_CODEC_ID_ADPCM_EA_R3:
                if (pkt->size >= 4)
                    pkt->duration = AV_RB32(pkt->data);
                break;
            case AV_CODEC_ID_ADPCM_IMA_EA_SEAD:
                pkt->duration = ret * 2 / ea->num_channels;
                break;
            case AV_CODEC_ID_PCM_S16LE_PLANAR:
            case AV_CODEC_ID_MP3:
                pkt->duration = num_samples;
                break;
            default:
                pkt->duration = chunk_size / (ea->bytes * ea->num_channels);
            }

            packet_read = 1;
            break;

        /* ending tag */
        case 0:
        case ISNe_TAG:
        case SCEl_TAG:
        case SEND_TAG:
        case SEEN_TAG:
            ret         = AVERROR(EIO);
            packet_read = 1;
            break;

        case MVIh_TAG:
        case kVGT_TAG:
        case pQGT_TAG:
        case TGQs_TAG:
        case MADk_TAG:
            key = AV_PKT_FLAG_KEY;
        case MVIf_TAG:
        case fVGT_TAG:
        case MADm_TAG:
        case MADe_TAG:
            avio_seek(pb, -8, SEEK_CUR);    // include chunk preamble
            chunk_size += 8;
            goto get_video_packet;

        case mTCD_TAG:
            avio_skip(pb, 8);               // skip ea DCT header
            chunk_size -= 8;
//.........这里部分代码省略.........

static int sox_probe(AVProbeData *p)
{
    if (AV_RL32(p->buf) == SOX_TAG || AV_RB32(p->buf) == SOX_TAG)
        return AVPROBE_SCORE_MAX;
    return 0;
}

VIDEOINFOHEADER2 *CLAVFVideoHelper::CreateVIH2(const AVStream* avstream, ULONG *size, std::string container)
{
  int extra = 0;
  BYTE *extradata = NULL;
  BOOL bZeroPad = FALSE;
  if (avstream->codec->codec_id == AV_CODEC_ID_VC1 && avstream->codec->extradata_size) {
    int i = 0;
    for (i = 0; i < (avstream->codec->extradata_size-4); i++) {
      uint32_t code = AV_RB32(avstream->codec->extradata + i);
      if (IS_VC1_MARKER(code))
        break;
    }
    if (i == 0) {
      bZeroPad = TRUE;
    } else if (i > 1) {
      DbgLog((LOG_TRACE, 10, L"CLAVFVideoHelper::CreateVIH2(): VC-1 extradata does not start at position 0/1, but %d", i));
    }
  }

  // Create a VIH that we'll convert
  VIDEOINFOHEADER *vih = CreateVIH(avstream, size, container);
  if (!vih) return NULL;

  if(avstream->codec->extradata_size > 0) {
    extra = avstream->codec->extradata_size;
    //increase extra size by one, because VIH2 requires one 0 byte between header and extra data
    if (bZeroPad) {
      extra++;
    }

    extradata = avstream->codec->extradata;
  }

  VIDEOINFOHEADER2 *vih2 = (VIDEOINFOHEADER2 *)CoTaskMemAlloc(sizeof(VIDEOINFOHEADER2) + extra); 
  if (!vih2) return NULL;
  memset(vih2, 0, sizeof(VIDEOINFOHEADER2));

  vih2->rcSource = vih->rcSource;
  vih2->rcTarget = vih->rcTarget;
  vih2->dwBitRate = vih->dwBitRate;
  vih2->dwBitErrorRate = vih->dwBitErrorRate;
  vih2->AvgTimePerFrame = vih->AvgTimePerFrame;

  // Calculate aspect ratio
  AVRational r = avstream->sample_aspect_ratio;
  AVRational rc = avstream->codec->sample_aspect_ratio;
  int num = vih->bmiHeader.biWidth, den = vih->bmiHeader.biHeight;
  if (r.den > 0 && r.num > 0) {
    av_reduce(&num, &den, (int64_t)r.num * num, (int64_t)r.den * den, 255);
  } else if (rc.den > 0 && rc.num > 0) {
    av_reduce(&num, &den, (int64_t)rc.num * num, (int64_t)rc.den * den, 255);
  } else {
    if (avstream->codec->codec_id == AV_CODEC_ID_RV40) {
      AVDictionaryEntry *w = av_dict_get(avstream->metadata, "rm_width", NULL, 0);
      AVDictionaryEntry *h = av_dict_get(avstream->metadata, "rm_height", NULL, 0);
      if (w && h) {
        num = atoi(w->value);
        den = atoi(h->value);
      }
    }
    av_reduce(&num, &den, num, den, num);
  }
  vih2->dwPictAspectRatioX = num;
  vih2->dwPictAspectRatioY = den;

  memcpy(&vih2->bmiHeader, &vih->bmiHeader, sizeof(BITMAPINFOHEADER));
  vih2->bmiHeader.biSize = sizeof(BITMAPINFOHEADER) + extra;

  vih2->dwInterlaceFlags = 0;
  vih2->dwCopyProtectFlags = 0;
  vih2->dwControlFlags = 0;
  vih2->dwReserved2 = 0;

  if(extra) {
    // The first byte after the infoheader has to be 0 in mpeg-ts
    if (bZeroPad) {
      *((BYTE*)vih2 + sizeof(VIDEOINFOHEADER2)) = 0;
      // after that, the extradata .. size reduced by one again
      memcpy((BYTE*)vih2 + sizeof(VIDEOINFOHEADER2) + 1, extradata, extra - 1);
    } else {
      memcpy((BYTE*)vih2 + sizeof(VIDEOINFOHEADER2), extradata, extra);
    }
  }

  // Free the VIH that we converted
  CoTaskMemFree(vih);

  *size = sizeof(VIDEOINFOHEADER2) + extra;
  return vih2;
}

/* aiff input */
static int aiff_read_header(AVFormatContext *s)
{
    int ret, size, filesize;
    int64_t offset = 0, position;
    uint32_t tag;
    unsigned version = AIFF_C_VERSION1;
    AVIOContext *pb = s->pb;
    AVStream * st;
    AIFFInputContext *aiff = s->priv_data;
    ID3v2ExtraMeta *id3v2_extra_meta = NULL;

    /* check FORM header */
    filesize = get_tag(pb, &tag);
    if (filesize < 0 || tag != MKTAG('F', 'O', 'R', 'M'))
        return AVERROR_INVALIDDATA;

    /* AIFF data type */
    tag = avio_rl32(pb);
    if (tag == MKTAG('A', 'I', 'F', 'F'))       /* Got an AIFF file */
        version = AIFF;
    else if (tag != MKTAG('A', 'I', 'F', 'C'))  /* An AIFF-C file then */
        return AVERROR_INVALIDDATA;

    filesize -= 4;

    st = avformat_new_stream(s, NULL);
    if (!st)
        return AVERROR(ENOMEM);

    while (filesize > 0) {
        /* parse different chunks */
        size = get_tag(pb, &tag);
        if (size < 0)
            return size;

        filesize -= size + 8;

        switch (tag) {
        case MKTAG('C', 'O', 'M', 'M'):     /* Common chunk */
            /* Then for the complete header info */
            st->nb_frames = get_aiff_header(s, size, version);
            if (st->nb_frames < 0)
                return st->nb_frames;
            if (offset > 0) // COMM is after SSND
                goto got_sound;
            break;
        case MKTAG('I', 'D', '3', ' '):
            position = avio_tell(pb);
            ff_id3v2_read(s, ID3v2_DEFAULT_MAGIC, &id3v2_extra_meta);
            if (id3v2_extra_meta)
                if ((ret = ff_id3v2_parse_apic(s, &id3v2_extra_meta)) < 0) {
                    ff_id3v2_free_extra_meta(&id3v2_extra_meta);
                    return ret;
                }
            ff_id3v2_free_extra_meta(&id3v2_extra_meta);
            if (position + size > avio_tell(pb))
                avio_skip(pb, position + size - avio_tell(pb));
            break;
        case MKTAG('F', 'V', 'E', 'R'):     /* Version chunk */
            version = avio_rb32(pb);
            break;
        case MKTAG('N', 'A', 'M', 'E'):     /* Sample name chunk */
            get_meta(s, "title"    , size);
            break;
        case MKTAG('A', 'U', 'T', 'H'):     /* Author chunk */
            get_meta(s, "author"   , size);
            break;
        case MKTAG('(', 'c', ')', ' '):     /* Copyright chunk */
            get_meta(s, "copyright", size);
            break;
        case MKTAG('A', 'N', 'N', 'O'):     /* Annotation chunk */
            get_meta(s, "comment"  , size);
            break;
        case MKTAG('S', 'S', 'N', 'D'):     /* Sampled sound chunk */
            aiff->data_end = avio_tell(pb) + size;
            offset = avio_rb32(pb);      /* Offset of sound data */
            avio_rb32(pb);               /* BlockSize... don't care */
            offset += avio_tell(pb);    /* Compute absolute data offset */
            if (st->codec->block_align && !pb->seekable)    /* Assume COMM already parsed */
                goto got_sound;
            if (!pb->seekable) {
                av_log(s, AV_LOG_ERROR, "file is not seekable\n");
                return -1;
            }
            avio_skip(pb, size - 8);
            break;
        case MKTAG('w', 'a', 'v', 'e'):
            if ((uint64_t)size > (1<<30))
                return -1;
            st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
            if (!st->codec->extradata)
                return AVERROR(ENOMEM);
            st->codec->extradata_size = size;
            avio_read(pb, st->codec->extradata, size);
            if (st->codec->codec_id == AV_CODEC_ID_QDM2 && size>=12*4 && !st->codec->block_align) {
                st->codec->block_align = AV_RB32(st->codec->extradata+11*4);
                aiff->block_duration = AV_RB32(st->codec->extradata+9*4);
            } else if (st->codec->codec_id == AV_CODEC_ID_QCELP) {
                char rate = 0;
//.........这里部分代码省略.........

static int flac_decode_frame(AVCodecContext *avctx, void *data,
                             int *got_frame_ptr, AVPacket *avpkt)
{
    AVFrame *frame     = data;
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    FLACContext *s = avctx->priv_data;
    int bytes_read = 0;
    int ret;

    *got_frame_ptr = 0;

    if (s->max_framesize == 0) {
        s->max_framesize =
            ff_flac_get_max_frame_size(s->max_blocksize ? s->max_blocksize : FLAC_MAX_BLOCKSIZE,
                                       FLAC_MAX_CHANNELS, 32);
    }

    if (buf_size > 5 && !memcmp(buf, "\177FLAC", 5)) {
        av_log(s->avctx, AV_LOG_DEBUG, "skiping flac header packet 1\n");
        return buf_size;
    }

    if (buf_size > 0 && (*buf & 0x7F) == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
        av_log(s->avctx, AV_LOG_DEBUG, "skiping vorbis comment\n");
        return buf_size;
    }

    /* check that there is at least the smallest decodable amount of data.
       this amount corresponds to the smallest valid FLAC frame possible.
       FF F8 69 02 00 00 9A 00 00 34 46 */
    if (buf_size < FLAC_MIN_FRAME_SIZE)
        return buf_size;

    /* check for inline header */
    if (AV_RB32(buf) == MKBETAG('f','L','a','C')) {
        if (!s->got_streaminfo && parse_streaminfo(s, buf, buf_size)) {
            av_log(s->avctx, AV_LOG_ERROR, "invalid header\n");
            return -1;
        }
        return get_metadata_size(buf, buf_size);
    }

    /* decode frame */
    init_get_bits(&s->gb, buf, buf_size*8);
    if (decode_frame(s) < 0) {
        av_log(s->avctx, AV_LOG_ERROR, "decode_frame() failed\n");
        return -1;
    }
    bytes_read = (get_bits_count(&s->gb)+7)/8;

    /* get output buffer */
    frame->nb_samples = s->blocksize;
    if ((ret = ff_get_buffer(avctx, frame)) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return ret;
    }

    s->dsp.decorrelate[s->ch_mode](frame->data, s->decoded, s->channels,
                                   s->blocksize, s->sample_shift);

    if (bytes_read > buf_size) {
        av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", bytes_read - buf_size);
        return -1;
    }
    if (bytes_read < buf_size) {
        av_log(s->avctx, AV_LOG_DEBUG, "underread: %d orig size: %d\n",
               buf_size - bytes_read, buf_size);
    }

    *got_frame_ptr = 1;

    return bytes_read;
}

static AVPictureType parse_picture_type(const uint8_t *buf, int buflen, CVC1HeaderParser *vc1Header)
{
  AVPictureType pictype = AV_PICTURE_TYPE_NONE;
  int skipped = 0;
  const BYTE *framestart = buf;
  if (IS_MARKER(AV_RB32(buf))) {
    framestart = NULL;
    const BYTE *start, *end, *next;
    next = buf;
    for (start = buf, end = buf + buflen; next < end; start = next) {
      if (AV_RB32(start) == VC1_CODE_FRAME) {
        framestart = start + 4;
        break;
      }
      next = find_next_marker(start + 4, end);
    }
  }
  if (framestart) {
    GetBitContext gb;
    init_get_bits(&gb, framestart, (buflen - (framestart-buf))*8);
    if (vc1Header->hdr.profile == PROFILE_ADVANCED) {
      int fcm = PROGRESSIVE;
      if (vc1Header->hdr.interlaced)
        fcm = decode012(&gb);
      if (fcm == ILACE_FIELD) {
        int fptype = get_bits(&gb, 3);
        pictype = (fptype & 2) ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
        if (fptype & 4) // B-picture
          pictype = (fptype & 2) ? AV_PICTURE_TYPE_BI : AV_PICTURE_TYPE_B;
      } else {
        switch (get_unary(&gb, 0, 4)) {
        case 0:
            pictype = AV_PICTURE_TYPE_P;
            break;
        case 1:
            pictype = AV_PICTURE_TYPE_B;
            break;
        case 2:
            pictype = AV_PICTURE_TYPE_I;
            break;
        case 3:
            pictype = AV_PICTURE_TYPE_BI;
            break;
        case 4:
            pictype = AV_PICTURE_TYPE_P; // skipped pic
            skipped = 1;
            break;
        }
      }
    } else {
      if (vc1Header->hdr.finterp)
        skip_bits1(&gb);
      skip_bits(&gb, 2); // framecnt
      if (vc1Header->hdr.rangered)
        skip_bits1(&gb);
      int pic = get_bits1(&gb);
      if (vc1Header->hdr.bframes) {
        if (!pic) {
          if (get_bits1(&gb)) {
            pictype = AV_PICTURE_TYPE_I;
          } else {
            pictype = AV_PICTURE_TYPE_B;
          }
        } else {
          pictype = AV_PICTURE_TYPE_P;
        }
      } else {
        pictype = pic ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
      }
    }
  }
  return pictype;
}

static int sunrast_decode_frame(AVCodecContext *avctx, void *data,
                                int *data_size, AVPacket *avpkt) {
    const uint8_t *buf       = avpkt->data;
    const uint8_t *buf_end   = avpkt->data + avpkt->size;
    SUNRASTContext * const s = avctx->priv_data;
    AVFrame *picture         = data;
    AVFrame * const p        = &s->picture;
    unsigned int w, h, depth, type, maptype, maplength, stride, x, y, len, alen;
    uint8_t *ptr;
    const uint8_t *bufstart = buf;

    if (avpkt->size < 32)
        return AVERROR_INVALIDDATA;

    if (AV_RB32(buf) != RAS_MAGIC) {
        av_log(avctx, AV_LOG_ERROR, "this is not sunras encoded data\n");
        return -1;
    }

    w         = AV_RB32(buf + 4);
    h         = AV_RB32(buf + 8);
    depth     = AV_RB32(buf + 12);
    type      = AV_RB32(buf + 20);
    maptype   = AV_RB32(buf + 24);
    maplength = AV_RB32(buf + 28);
    buf      += 32;

    if (type == RT_FORMAT_TIFF || type == RT_FORMAT_IFF || type == RT_EXPERIMENTAL) {
        av_log_ask_for_sample(avctx, "unsupported (compression) type\n");
        return AVERROR_PATCHWELCOME;
    }
    if (type > RT_FORMAT_IFF) {
        av_log(avctx, AV_LOG_ERROR, "invalid (compression) type\n");
        return -1;
    }
    if (av_image_check_size(w, h, 0, avctx)) {
        av_log(avctx, AV_LOG_ERROR, "invalid image size\n");
        return -1;
    }
    if (maptype & ~1) {
        av_log(avctx, AV_LOG_ERROR, "invalid colormap type\n");
        return -1;
    }


    switch (depth) {
        case 1:
            avctx->pix_fmt = PIX_FMT_MONOWHITE;
            break;
        case 8:
            avctx->pix_fmt = PIX_FMT_PAL8;
            break;
        case 24:
            avctx->pix_fmt = (type == RT_FORMAT_RGB) ? PIX_FMT_RGB24 : PIX_FMT_BGR24;
            break;
        default:
            av_log(avctx, AV_LOG_ERROR, "invalid depth\n");
            return -1;
    }

    if (p->data[0])
        avctx->release_buffer(avctx, p);

    if (w != avctx->width || h != avctx->height)
        avcodec_set_dimensions(avctx, w, h);
    if (avctx->get_buffer(avctx, p) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return -1;
    }

    p->pict_type = AV_PICTURE_TYPE_I;

    if (buf_end - buf < maplength)
        return AVERROR_INVALIDDATA;

    if (depth != 8 && maplength) {
        av_log(avctx, AV_LOG_WARNING, "useless colormap found or file is corrupted, trying to recover\n");

    } else if (depth == 8) {
        unsigned int len = maplength / 3;

        if (!maplength) {
            av_log(avctx, AV_LOG_ERROR, "colormap expected\n");
            return -1;
        }
        if (maplength % 3 || maplength > 768) {
            av_log(avctx, AV_LOG_WARNING, "invalid colormap length\n");
            return -1;
        }

        ptr = p->data[1];
        for (x = 0; x < len; x++, ptr += 4)
            *(uint32_t *)ptr = (buf[x] << 16) + (buf[len + x] << 8) + buf[len + len + x];
    }

    buf += maplength;

    ptr    = p->data[0];
    stride = p->linesize[0];

//.........这里部分代码省略.........

static int libschroedinger_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                                        const AVFrame *frame, int *got_packet)
{
    int enc_size = 0;
    SchroEncoderParams *p_schro_params = avctx->priv_data;
    SchroEncoder *encoder = p_schro_params->encoder;
    struct FFSchroEncodedFrame *p_frame_output = NULL;
    int go = 1;
    SchroBuffer *enc_buf;
    int presentation_frame;
    int parse_code;
    int last_frame_in_sequence = 0;
    int pkt_size, ret;

    if (!frame) {
        /* Push end of sequence if not already signalled. */
        if (!p_schro_params->eos_signalled) {
            schro_encoder_end_of_stream(encoder);
            p_schro_params->eos_signalled = 1;
        }
    } else {
        /* Allocate frame data to schro input buffer. */
        SchroFrame *in_frame = libschroedinger_frame_from_data(avctx, frame);
        if (!in_frame)
            return AVERROR(ENOMEM);
        /* Load next frame. */
        schro_encoder_push_frame(encoder, in_frame);
    }

    if (p_schro_params->eos_pulled)
        go = 0;

    /* Now check to see if we have any output from the encoder. */
    while (go) {
        int err;
        SchroStateEnum state;
        state = schro_encoder_wait(encoder);
        switch (state) {
        case SCHRO_STATE_HAVE_BUFFER:
        case SCHRO_STATE_END_OF_STREAM:
            enc_buf = schro_encoder_pull(encoder, &presentation_frame);
            if (enc_buf->length <= 0)
                return AVERROR_BUG;
            parse_code = enc_buf->data[4];

            /* All non-frame data is prepended to actual frame data to
             * be able to set the pts correctly. So we don't write data
             * to the frame output queue until we actually have a frame
             */
            if ((err = av_reallocp(&p_schro_params->enc_buf,
                                   p_schro_params->enc_buf_size +
                                   enc_buf->length)) < 0) {
                p_schro_params->enc_buf_size = 0;
                return err;
            }

            memcpy(p_schro_params->enc_buf + p_schro_params->enc_buf_size,
                   enc_buf->data, enc_buf->length);
            p_schro_params->enc_buf_size += enc_buf->length;


            if (state == SCHRO_STATE_END_OF_STREAM) {
                p_schro_params->eos_pulled = 1;
                go = 0;
            }

            if (!SCHRO_PARSE_CODE_IS_PICTURE(parse_code)) {
                schro_buffer_unref(enc_buf);
                break;
            }

            /* Create output frame. */
            p_frame_output = av_mallocz(sizeof(FFSchroEncodedFrame));
            if (!p_frame_output)
                return AVERROR(ENOMEM);
            /* Set output data. */
            p_frame_output->size     = p_schro_params->enc_buf_size;
            p_frame_output->p_encbuf = p_schro_params->enc_buf;
            if (SCHRO_PARSE_CODE_IS_INTRA(parse_code) &&
                SCHRO_PARSE_CODE_IS_REFERENCE(parse_code))
                p_frame_output->key_frame = 1;

            /* Parse the coded frame number from the bitstream. Bytes 14
             * through 17 represesent the frame number. */
            p_frame_output->frame_num = AV_RB32(enc_buf->data + 13);

            ff_schro_queue_push_back(&p_schro_params->enc_frame_queue,
                                     p_frame_output);
            p_schro_params->enc_buf_size = 0;
            p_schro_params->enc_buf      = NULL;

            schro_buffer_unref(enc_buf);

            break;

        case SCHRO_STATE_NEED_FRAME:
            go = 0;
            break;

        case SCHRO_STATE_AGAIN:
//.........这里部分代码省略.........

static int a64_write_packet(struct AVFormatContext *s, AVPacket *pkt)
{
    AVCodecContext *avctx = s->streams[0]->codec;
    A64MuxerContext *c = s->priv_data;
    int i, j;
    int ch_chunksize;
    int lifetime;
    int frame_count;
    int charset_size;
    int frame_size;
    int num_frames;

    /* fetch values from extradata */
    switch (avctx->codec->id) {
    case CODEC_ID_A64_MULTI:
    case CODEC_ID_A64_MULTI5:
        if(c->interleaved) {
            /* Write interleaved, means we insert chunks of the future charset before each current frame.
             * Reason: if we load 1 charset + corresponding frames in one block on c64, we need to store
             * them first and then display frame by frame to keep in sync. Thus we would read and write
             * the data for colram from/to ram first and waste too much time. If we interleave and send the
             * charset beforehand, we assemble a new charset chunk by chunk, write current screen data to
             * screen-ram to be displayed and decode the colram directly to colram-location $d800 during
             * the overscan, while reading directly from source.
             * This is the only way so far, to achieve 25fps on c64 */
            if(avctx->extradata) {
                /* fetch values from extradata */
                lifetime     = AV_RB32(avctx->extradata + 0);
                frame_count  = AV_RB32(avctx->extradata + 4);
                charset_size = AV_RB32(avctx->extradata + 8);
                frame_size   = AV_RB32(avctx->extradata + 12);

                /* TODO: sanity checks? */
            } else {
                av_log(avctx, AV_LOG_ERROR, "extradata not set\n");
                return AVERROR(EINVAL);
            }

            ch_chunksize=charset_size/lifetime;
            /* TODO: check if charset/size is % lifetime, but maybe check in codec */

            if(pkt->data) num_frames = lifetime;
            else num_frames = c->prev_frame_count;

            for(i = 0; i < num_frames; i++) {
                if(pkt->data) {
                    /* if available, put newest charset chunk into buffer */
                    put_buffer(s->pb, pkt->data + ch_chunksize * i, ch_chunksize);
                } else {
                    /* a bit ugly, but is there an alternative to put many zeros? */
                    for(j = 0; j < ch_chunksize; j++) put_byte(s->pb, 0);
                }

                if(c->prev_pkt.data) {
                    /* put frame (screen + colram) from last packet into buffer */
                    put_buffer(s->pb, c->prev_pkt.data + charset_size + frame_size * i, frame_size);
                } else {
                    /* a bit ugly, but is there an alternative to put many zeros? */
                    for(j = 0; j < frame_size; j++) put_byte(s->pb, 0);
                }
            }

            /* backup current packet for next turn */
            if(pkt->data) {
                /* no backup packet yet? create one! */
                if(!c->prev_pkt.data) av_new_packet(&c->prev_pkt, pkt->size);
                /* we have a packet and data is big enough, reuse it */
                if(c->prev_pkt.data && c->prev_pkt.size >= pkt->size) {
                    memcpy(c->prev_pkt.data, pkt->data, pkt->size);
                    c->prev_pkt.size = pkt->size;
                } else {
                    av_log(avctx, AV_LOG_ERROR, "Too less memory for prev_pkt.\n");
                    return AVERROR(ENOMEM);
                }
            }

            c->prev_frame_count = frame_count;
            break;
        }
    default:
        /* Write things as is. Nice for self-contained frames from non-multicolor modes or if played
         * directly from ram and not from a streaming device (rrnet/mmc) */
        if(pkt) put_buffer(s->pb, pkt->data, pkt->size);
        break;
    }

    put_flush_packet(s->pb);
    return 0;
}

static int avui_decode_frame(AVCodecContext *avctx, void *data,
                             int *got_frame, AVPacket *avpkt)
{
    int ret;
    AVFrame *pic = data;
    const uint8_t *src = avpkt->data, *extradata = avctx->extradata;
    const uint8_t *srca;
    uint8_t *y, *u, *v, *a;
    int transparent, interlaced = 1, skip, opaque_length, i, j, k;
    uint32_t extradata_size = avctx->extradata_size;

    while (extradata_size >= 24) {
        uint32_t atom_size = AV_RB32(extradata);
        if (!memcmp(&extradata[4], "APRGAPRG0001", 12)) {
            interlaced = extradata[19] != 1;
            break;
        }
        if (atom_size && atom_size <= extradata_size) {
            extradata      += atom_size;
            extradata_size -= atom_size;
        } else {
            break;
        }
    }
    if (avctx->height == 486) {
        skip = 10;
    } else {
        skip = 16;
    }
    opaque_length = 2 * avctx->width * (avctx->height + skip) + 4 * interlaced;
    if (avpkt->size < opaque_length) {
        av_log(avctx, AV_LOG_ERROR, "Insufficient input data.\n");
        return AVERROR(EINVAL);
    }
    transparent = avctx->bits_per_coded_sample == 32 &&
                  avpkt->size >= opaque_length * 2 + 4;
    srca = src + opaque_length + 5;

    if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
        return ret;

    pic->key_frame = 1;
    pic->pict_type = AV_PICTURE_TYPE_I;

    if (!interlaced) {
        src  += avctx->width * skip;
        srca += avctx->width * skip;
    }

    for (i = 0; i < interlaced + 1; i++) {
        src  += avctx->width * skip;
        srca += avctx->width * skip;
        if (interlaced && avctx->height == 486) {
            y = pic->data[0] + (1 - i) * pic->linesize[0];
            u = pic->data[1] + (1 - i) * pic->linesize[1];
            v = pic->data[2] + (1 - i) * pic->linesize[2];
            a = pic->data[3] + (1 - i) * pic->linesize[3];
        } else {
            y = pic->data[0] + i * pic->linesize[0];
            u = pic->data[1] + i * pic->linesize[1];
            v = pic->data[2] + i * pic->linesize[2];
            a = pic->data[3] + i * pic->linesize[3];
        }

        for (j = 0; j < avctx->height >> interlaced; j++) {
            for (k = 0; k < avctx->width >> 1; k++) {
                u[    k    ] = *src++;
                y[2 * k    ] = *src++;
                a[2 * k    ] = 0xFF - (transparent ? *srca++ : 0);
                srca++;
                v[    k    ] = *src++;
                y[2 * k + 1] = *src++;
                a[2 * k + 1] = 0xFF - (transparent ? *srca++ : 0);
                srca++;
            }

            y += (interlaced + 1) * pic->linesize[0];
            u += (interlaced + 1) * pic->linesize[1];
            v += (interlaced + 1) * pic->linesize[2];
            a += (interlaced + 1) * pic->linesize[3];
        }
        src  += 4;
        srca += 4;
    }
    *got_frame       = 1;

    return avpkt->size;
}

static int mp3_read_probe(AVProbeData *p)
{
    int max_frames, first_frames = 0;
    int frames, ret;
    uint32_t header;
    uint8_t *buf, *buf0, *buf2, *end;

    buf0 = p->buf;
    end = p->buf + p->buf_size - sizeof(uint32_t);
    while(buf0 < end && !*buf0)
        buf0++;

    max_frames = 0;
    buf = buf0;

    for(; buf < end; buf= buf2+1) {
        buf2 = buf;

        for(frames = 0; buf2 < end; frames++) {
            MPADecodeHeader h;

            header = AV_RB32(buf2);
            ret = avpriv_mpegaudio_decode_header(&h, header);
            if (ret != 0)
                break;
            buf2 += h.frame_size;
        }
        max_frames = FFMAX(max_frames, frames);
        if(buf == buf0)
            first_frames= frames;
    }
    // keep this in sync with ac3 probe, both need to avoid
    // issues with MPEG-files!
    if (first_frames >= 10)
        return AVPROBE_SCORE_EXTENSION + 5;
    if (first_frames >= 4)
        return AVPROBE_SCORE_EXTENSION + 1;

    if (max_frames) {
        int pes = 0, i;
        unsigned int code = -1;

#define VIDEO_ID 0x000001e0
#define AUDIO_ID 0x000001c0
        /* do a search for mpegps headers to be able to properly bias
         * towards mpegps if we detect this stream as both. */
        for (i = 0; i<p->buf_size; i++) {
            code = (code << 8) + p->buf[i];
            if ((code & 0xffffff00) == 0x100) {
                if     ((code & 0x1f0) == VIDEO_ID) pes++;
                else if((code & 0x1e0) == AUDIO_ID) pes++;
            }
        }

        if (pes)
            max_frames = (max_frames + pes - 1) / pes;
    }
    if      (max_frames >  500) return AVPROBE_SCORE_EXTENSION;
    else if (max_frames >= 4)   return AVPROBE_SCORE_EXTENSION / 2;
    else if (max_frames >= 1)   return 1;
    else                        return 0;
//mpegps_mp3_unrecognized_format.mpg has max_frames=3
}

static int film_read_header(AVFormatContext *s,
                            AVFormatParameters *ap)
{
    FilmDemuxContext *film = s->priv_data;
    ByteIOContext *pb = s->pb;
    AVStream *st;
    unsigned char scratch[256];
    int i;
    unsigned int data_offset;
    unsigned int audio_frame_counter;

    film->sample_table = NULL;
    film->stereo_buffer = NULL;
    film->stereo_buffer_size = 0;

    /* load the main FILM header */
    if (get_buffer(pb, scratch, 16) != 16)
        return AVERROR(EIO);
    data_offset = AV_RB32(&scratch[4]);
    film->version = AV_RB32(&scratch[8]);

    /* load the FDSC chunk */
    if (film->version == 0) {
        /* special case for Lemmings .film files; 20-byte header */
        if (get_buffer(pb, scratch, 20) != 20)
            return AVERROR(EIO);
        /* make some assumptions about the audio parameters */
        film->audio_type = CODEC_ID_PCM_S8;
        film->audio_samplerate = 22050;
        film->audio_channels = 1;
        film->audio_bits = 8;
    } else {
        /* normal Saturn .cpk files; 32-byte header */
        if (get_buffer(pb, scratch, 32) != 32)
            return AVERROR(EIO);
        film->audio_samplerate = AV_RB16(&scratch[24]);;
        film->audio_channels = scratch[21];
        film->audio_bits = scratch[22];
        if (film->audio_bits == 8)
            film->audio_type = CODEC_ID_PCM_S8;
        else if (film->audio_bits == 16)
            film->audio_type = CODEC_ID_PCM_S16BE;
        else
            film->audio_type = 0;
    }

    if (AV_RB32(&scratch[0]) != FDSC_TAG)
        return AVERROR_INVALIDDATA;

    if (AV_RB32(&scratch[8]) == CVID_TAG) {
        film->video_type = CODEC_ID_CINEPAK;
    } else
        film->video_type = 0;

    /* initialize the decoder streams */
    if (film->video_type) {
        st = av_new_stream(s, 0);
        if (!st)
            return AVERROR(ENOMEM);
        film->video_stream_index = st->index;
        st->codec->codec_type = CODEC_TYPE_VIDEO;
        st->codec->codec_id = film->video_type;
        st->codec->codec_tag = 0;  /* no fourcc */
        st->codec->width = AV_RB32(&scratch[16]);
        st->codec->height = AV_RB32(&scratch[12]);
    }

    if (film->audio_type) {
        st = av_new_stream(s, 0);
        if (!st)
            return AVERROR(ENOMEM);
        film->audio_stream_index = st->index;
        st->codec->codec_type = CODEC_TYPE_AUDIO;
        st->codec->codec_id = film->audio_type;
        st->codec->codec_tag = 1;
        st->codec->channels = film->audio_channels;
        st->codec->bits_per_sample = film->audio_bits;
        st->codec->sample_rate = film->audio_samplerate;
        st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
            st->codec->bits_per_sample;
        st->codec->block_align = st->codec->channels *
            st->codec->bits_per_sample / 8;
    }

    /* load the sample table */
    if (get_buffer(pb, scratch, 16) != 16)
        return AVERROR(EIO);
    if (AV_RB32(&scratch[0]) != STAB_TAG)
        return AVERROR_INVALIDDATA;
    film->base_clock = AV_RB32(&scratch[8]);
    film->sample_count = AV_RB32(&scratch[12]);
    if(film->sample_count >= UINT_MAX / sizeof(film_sample_t))
        return -1;
    film->sample_table = av_malloc(film->sample_count * sizeof(film_sample_t));

    for(i=0; i<s->nb_streams; i++)
        av_set_pts_info(s->streams[i], 33, 1, film->base_clock);

    audio_frame_counter = 0;
    for (i = 0; i < film->sample_count; i++) {
//.........这里部分代码省略.........

static int film_read_header(AVFormatContext *s)
{
    FilmDemuxContext *film = s->priv_data;
    AVIOContext *pb = s->pb;
    AVStream *st;
    unsigned char scratch[256];
    int i, ret;
    unsigned int data_offset;
    unsigned int audio_frame_counter;
    unsigned int video_frame_counter;

    film->sample_table = NULL;

    /* load the main FILM header */
    if (avio_read(pb, scratch, 16) != 16)
        return AVERROR(EIO);
    data_offset = AV_RB32(&scratch[4]);
    film->version = AV_RB32(&scratch[8]);

    /* load the FDSC chunk */
    if (film->version == 0) {
        /* special case for Lemmings .film files; 20-byte header */
        if (avio_read(pb, scratch, 20) != 20)
            return AVERROR(EIO);
        /* make some assumptions about the audio parameters */
        film->audio_type = AV_CODEC_ID_PCM_S8;
        film->audio_samplerate = 22050;
        film->audio_channels = 1;
        film->audio_bits = 8;
    } else {
        /* normal Saturn .cpk files; 32-byte header */
        if (avio_read(pb, scratch, 32) != 32)
            return AVERROR(EIO);
        film->audio_samplerate = AV_RB16(&scratch[24]);
        film->audio_channels = scratch[21];
        if (!film->audio_channels || film->audio_channels > 2) {
            av_log(s, AV_LOG_ERROR,
                   "Invalid number of channels: %d\n", film->audio_channels);
            return AVERROR_INVALIDDATA;
        }
        film->audio_bits = scratch[22];
        if (scratch[23] == 2)
            film->audio_type = AV_CODEC_ID_ADPCM_ADX;
        else if (film->audio_channels > 0) {
            if (film->audio_bits == 8)
                film->audio_type = AV_CODEC_ID_PCM_S8_PLANAR;
            else if (film->audio_bits == 16)
                film->audio_type = AV_CODEC_ID_PCM_S16BE_PLANAR;
            else
                film->audio_type = AV_CODEC_ID_NONE;
        } else
            film->audio_type = AV_CODEC_ID_NONE;
    }

    if (AV_RB32(&scratch[0]) != FDSC_TAG)
        return AVERROR_INVALIDDATA;

    if (AV_RB32(&scratch[8]) == CVID_TAG) {
        film->video_type = AV_CODEC_ID_CINEPAK;
    } else if (AV_RB32(&scratch[8]) == RAW_TAG) {
        film->video_type = AV_CODEC_ID_RAWVIDEO;
    } else {
        film->video_type = AV_CODEC_ID_NONE;
    }

    /* initialize the decoder streams */
    if (film->video_type) {
        st = avformat_new_stream(s, NULL);
        if (!st)
            return AVERROR(ENOMEM);
        film->video_stream_index = st->index;
        st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
        st->codec->codec_id = film->video_type;
        st->codec->codec_tag = 0;  /* no fourcc */
        st->codec->width = AV_RB32(&scratch[16]);
        st->codec->height = AV_RB32(&scratch[12]);

        if (film->video_type == AV_CODEC_ID_RAWVIDEO) {
            if (scratch[20] == 24) {
                st->codec->pix_fmt = AV_PIX_FMT_RGB24;
            } else {
                av_log(s, AV_LOG_ERROR, "raw video is using unhandled %dbpp\n", scratch[20]);
                return -1;
            }
        }
    }

    if (film->audio_type) {
        st = avformat_new_stream(s, NULL);
        if (!st)
            return AVERROR(ENOMEM);
        film->audio_stream_index = st->index;
        st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
        st->codec->codec_id = film->audio_type;
        st->codec->codec_tag = 1;
        st->codec->channels = film->audio_channels;
        st->codec->sample_rate = film->audio_samplerate;

        if (film->audio_type == AV_CODEC_ID_ADPCM_ADX) {
            st->codec->bits_per_coded_sample = 18 * 8 / 32;
//.........这里部分代码省略.........

static int wsvqa_read_header(AVFormatContext *s,
                             AVFormatParameters *ap)
{
    WsVqaDemuxContext *wsvqa = s->priv_data;
    AVIOContext *pb = s->pb;
    AVStream *st;
    unsigned char *header;
    unsigned char scratch[VQA_PREAMBLE_SIZE];
    unsigned int chunk_tag;
    unsigned int chunk_size;

    /* initialize the video decoder stream */
    st = av_new_stream(s, 0);
    if (!st)
        return AVERROR(ENOMEM);
    av_set_pts_info(st, 33, 1, VQA_FRAMERATE);
    wsvqa->video_stream_index = st->index;
    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
    st->codec->codec_id = CODEC_ID_WS_VQA;
    st->codec->codec_tag = 0;  /* no fourcc */

    /* skip to the start of the VQA header */
    url_fseek(pb, 20, SEEK_SET);

    /* the VQA header needs to go to the decoder */
    st->codec->extradata_size = VQA_HEADER_SIZE;
    st->codec->extradata = av_mallocz(VQA_HEADER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
    header = (unsigned char *)st->codec->extradata;
    if (avio_read(pb, st->codec->extradata, VQA_HEADER_SIZE) !=
        VQA_HEADER_SIZE) {
        av_free(st->codec->extradata);
        return AVERROR(EIO);
    }
    st->codec->width = AV_RL16(&header[6]);
    st->codec->height = AV_RL16(&header[8]);

    /* initialize the audio decoder stream for VQA v1 or nonzero samplerate */
    if (AV_RL16(&header[24]) || (AV_RL16(&header[0]) == 1 && AV_RL16(&header[2]) == 1)) {
        st = av_new_stream(s, 0);
        if (!st)
            return AVERROR(ENOMEM);
        av_set_pts_info(st, 33, 1, VQA_FRAMERATE);
        st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
        if (AV_RL16(&header[0]) == 1)
            st->codec->codec_id = CODEC_ID_WESTWOOD_SND1;
        else
            st->codec->codec_id = CODEC_ID_ADPCM_IMA_WS;
        st->codec->codec_tag = 0;  /* no tag */
        st->codec->sample_rate = AV_RL16(&header[24]);
        if (!st->codec->sample_rate)
            st->codec->sample_rate = 22050;
        st->codec->channels = header[26];
        if (!st->codec->channels)
            st->codec->channels = 1;
        st->codec->bits_per_coded_sample = 16;
        st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
            st->codec->bits_per_coded_sample / 4;
        st->codec->block_align = st->codec->channels * st->codec->bits_per_coded_sample;

        wsvqa->audio_stream_index = st->index;
        wsvqa->audio_samplerate = st->codec->sample_rate;
        wsvqa->audio_channels = st->codec->channels;
        wsvqa->audio_frame_counter = 0;
    }

    /* there are 0 or more chunks before the FINF chunk; iterate until
     * FINF has been skipped and the file will be ready to be demuxed */
    do {
        if (avio_read(pb, scratch, VQA_PREAMBLE_SIZE) != VQA_PREAMBLE_SIZE) {
            av_free(st->codec->extradata);
            return AVERROR(EIO);
        }
        chunk_tag = AV_RB32(&scratch[0]);
        chunk_size = AV_RB32(&scratch[4]);

        /* catch any unknown header tags, for curiousity */
        switch (chunk_tag) {
        case CINF_TAG:
        case CINH_TAG:
        case CIND_TAG:
        case PINF_TAG:
        case PINH_TAG:
        case PIND_TAG:
        case FINF_TAG:
        case CMDS_TAG:
            break;

        default:
            av_log (s, AV_LOG_ERROR, " note: unknown chunk seen (%c%c%c%c)\n",
                scratch[0], scratch[1],
                scratch[2], scratch[3]);
            break;
        }

        url_fseek(pb, chunk_size, SEEK_CUR);
    } while (chunk_tag != FINF_TAG);

    return 0;
}