static int eightsvx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt) { EightSvxContext *esc = avctx->priv_data; int n, out_data_size; int ch, ret; uint8_t *src; /* decode and interleave the first packet */ if (!esc->samples && avpkt) { int packet_size = avpkt->size; if (packet_size % avctx->channels) { av_log(avctx, AV_LOG_WARNING, "Packet with odd size, ignoring last byte\n"); if (packet_size < avctx->channels) return packet_size; packet_size -= packet_size % avctx->channels; } esc->samples_size = !esc->table ? packet_size : avctx->channels + (packet_size-avctx->channels) * 2; if (!(esc->samples = av_malloc(esc->samples_size))) return AVERROR(ENOMEM); /* decompress */ if (esc->table) { const uint8_t *buf = avpkt->data; uint8_t *dst; int buf_size = avpkt->size; int i, n = esc->samples_size; if (buf_size < 2) { av_log(avctx, AV_LOG_ERROR, "packet size is too small\n"); return AVERROR(EINVAL); } /* the uncompressed starting value is contained in the first byte */ dst = esc->samples; for (i = 0; i < avctx->channels; i++) { *(dst++) = buf[0]+128; delta_decode(dst, buf + 1, buf_size / avctx->channels - 1, (buf[0]+128)&0xFF, esc->table); buf += buf_size / avctx->channels; dst += n / avctx->channels - 1; } } else { raw_decode(esc->samples, avpkt->data, esc->samples_size); } } /* get output buffer */ av_assert1(!(esc->samples_size % avctx->channels || esc->samples_idx % avctx->channels)); esc->frame.nb_samples = FFMIN(MAX_FRAME_SIZE, esc->samples_size - esc->samples_idx) / avctx->channels; if ((ret = avctx->get_buffer(avctx, &esc->frame)) < 0) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return ret; } *got_frame_ptr = 1; *(AVFrame *)data = esc->frame; out_data_size = esc->frame.nb_samples; for (ch = 0; ch<avctx->channels; ch++) { src = esc->samples + esc->samples_idx / avctx->channels + ch * esc->samples_size / avctx->channels; memcpy(esc->frame.data[ch], src, out_data_size); } out_data_size *= avctx->channels; esc->samples_idx += out_data_size; return esc->table ? (avctx->frame_number == 0)*2 + out_data_size / 2 : out_data_size; }