CODEWITHSUNDEEP
apidecodeh.264libavmux
user11903678
user11903678

Reputation:

What does it mean "invalid NAL unit size" for h.264 decoder?

I want to transmux a .mkv file to .mp4 using Libav but when I try to decode the video h.264 stream there is a malfunction in my code

Invalid NAL unit size 21274662>141

Error splitting the input into NAL units

The stream seems to contain AVCC extradata with Annex B formatted data which is invalid. no frame!

Could not send paket for decoding ("error invalid data when processing input")

A relevant section of code is available below.

while(!(ret = av_read_frame(ifmt_ctx, &input_packet))&&(ret>=0)){

         if ((ret = avcodec_send_packet(avctx, &input_packet)) < 0) {
            fprintf(stderr, "Could not send packet for decoding (error '%s')\n",get_error_text(ret));
            return ret;
        }

        ret = avcodec_receive_frame(avctx, iframe);
        if (ret == AVERROR(EAGAIN)) {
            goto read_another_frame;
            /* If the end of the input file is reached, stop decoding. */
        } else if (ret == AVERROR_EOF) {
            break;
        } else if (ret < 0) {
            fprintf(stderr, "Could not decode frame (error '%s')\n",get_error_text(ret));
            break;
        }
        // Default case: encode data
         else {

        }

I use mainly the new API (send / receive packet /frame) and the confusion exists because it seems like h.264 needs a special implementation. I'm looking forward to any idea from where I should start the debugging.

Upvotes: 6

Views: 37576

Answers (2)

emdou
emdou

Reputation: 331

I think this is because you're not checking if the packet is from a video stream. In other words your code sends all packets from all streams to the h.264 codec.

In this case, a way to tackle the problem would be to add a simple condition that skips non video steam packets as such:

if (input_packet->stream_index != video_stream->index) continue;

Assuming video_stream is the first video stream encoutered in the format context stream array ifmt_ctx->streams.

Upvotes: 0

szatmary
szatmary

Reputation: 31110

It means the ES format is not compatible with the container. Read this: Possible Locations for Sequence/Picture Parameter Set(s) for H.264 Stream

Upvotes: 3

Related Questions