static int png_decode_idat(PNGDecContext *s, int length) { int ret; s->zstream.avail_in = FFMIN(length, bytestream2_get_bytes_left(&s->gb)); s->zstream.next_in = (unsigned char *)s->gb.buffer; bytestream2_skip(&s->gb, length); /* decode one line if possible */ while (s->zstream.avail_in > 0) { ret = inflate(&s->zstream, Z_PARTIAL_FLUSH); if (ret != Z_OK && ret != Z_STREAM_END) { av_log(s->avctx, AV_LOG_ERROR, "inflate returned error %d\n", ret); return AVERROR_EXTERNAL; } if (s->zstream.avail_out == 0) { if (!(s->state & PNG_ALLIMAGE)) { png_handle_row(s); } s->zstream.avail_out = s->crow_size; s->zstream.next_out = s->crow_buf; } if (ret == Z_STREAM_END && s->zstream.avail_in > 0) { av_log(NULL, AV_LOG_WARNING, "%d undecompressed bytes left in buffer\n", s->zstream.avail_in); return 0; } } return 0; }