Function av_write_frame

libavformat/mux.c:1176–1221

}

int av_write_frame(AVFormatContext *s, AVPacket *in)
{
    FFFormatContext *const si = ffformatcontext(s);
    AVPacket *pkt = si->parse_pkt;
    int ret;

    if (!in) {
        if (ffofmt(s->oformat)->flags_internal & FF_OFMT_FLAG_ALLOW_FLUSH) {
            ret = ffofmt(s->oformat)->write_packet(s, NULL);
            flush_if_needed(s);
            if (ret >= 0 && s->pb && s->pb->error < 0)
                ret = s->pb->error;
            return ret;
        }
        return 1;
    }

    if (in->flags & AV_PKT_FLAG_UNCODED_FRAME) {
        pkt = in;
    } else {
        /* We don't own in, so we have to make sure not to modify it.
         * (ff_write_chained() relies on this fact.)
         * The following avoids copying in's data unnecessarily.
         * Copying side data is unavoidable as a bitstream filter
         * may change it, e.g. free it on errors. */
        pkt->data = in->data;
        pkt->size = in->size;
        ret = av_packet_copy_props(pkt, in);
        if (ret < 0)
            return ret;
        if (in->buf) {
            pkt->buf = av_buffer_ref(in->buf);
            if (!pkt->buf) {
                ret = AVERROR(ENOMEM);
                goto fail;
            }
        }
    }

    ret = write_packets_common(s, pkt, 0/*non-interleaved*/);

fail:
    // Uncoded frames using the noninterleaved codepath are also freed here
    av_packet_unref(pkt);
    return ret;
}

int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
{