Function amf_decode_frame

libavcodec/amfdec.c:555–655

}

static int amf_decode_frame(AVCodecContext *avctx, struct AVFrame *frame)
{
    AMFDecoderContext *ctx = avctx->priv_data;
    AMFBuffer           *buf;
    AMF_RESULT          res;
    int                 got_frame = 0;
    AVPacket            *avpkt = ctx->in_pkt;

    if (!ctx->decoder)
        return AVERROR(EINVAL);

    // get packet if needed
    if(!ctx->drain){
        if(ctx->resolution_changed)
            ctx->resolution_changed = 0;
        else{
            int ret;
            av_packet_unref(avpkt);
            ret = ff_decode_get_packet(avctx, avpkt);
            if (ret < 0 && ret != AVERROR_EOF)
                return ret;
            if (ret == AVERROR_EOF) {
                //nothing to consume, start external drain
                ctx->decoder->pVtbl->Drain(ctx->decoder);
                ctx->drain = 1;
            }
        }
    }

    if(!ctx->drain){
        // submit frame
        res = amf_buffer_from_packet(avctx, avpkt, &buf);
        AMF_RETURN_IF_FALSE(avctx, res == AMF_OK, 0, "Cannot convert AVPacket to AMFbuffer");
        do{
            res = ctx->decoder->pVtbl->SubmitInput(ctx->decoder, (AMFData*) buf);
            if(res == AMF_DECODER_NO_FREE_SURFACES)
            {
                av_usleep(100);
            }
        } while (res == AMF_DECODER_NO_FREE_SURFACES);

        buf->pVtbl->Release(buf);

        if(res == AMF_DECODER_NO_FREE_SURFACES) {
            // input is not consumed, need to QueryOutput and submit again
            av_log(avctx, AV_LOG_VERBOSE, "SubmitInput() returned NO_FREE_SURFACES and came out of loop - should never happen\n");
            res = AMF_OK;
        } else if (res == AMF_RESOLUTION_CHANGED) {
            //input is not consumed, start internal drain
            ctx->decoder->pVtbl->Drain(ctx->decoder);
            ctx->drain = 1;
            // process resolution_changed when internal drain is complete
            ctx->resolution_changed = 1;
            res = AMF_OK;
        } else if (res != AMF_OK && res != AMF_NEED_MORE_INPUT && res != AMF_REPEAT) {
            av_log(avctx, AV_LOG_ERROR, "SubmitInput() returned error %d\n", res);
            return AVERROR(EINVAL);
        }