static int ogg_build_flac_headers(const uint8_t *extradata, int extradata_size, OGGStreamContext *oggstream, int bitexact) { const char *vendor = bitexact ? "ffmpeg" : LIBAVFORMAT_IDENT; uint8_t *p; if (extradata_size != 34) return -1; oggstream->header_len[0] = 51; oggstream->header[0] = av_mallocz(51); // per ogg flac specs p = oggstream->header[0]; bytestream_put_byte(&p, 0x7F); bytestream_put_buffer(&p, "FLAC", 4); bytestream_put_byte(&p, 1); // major version bytestream_put_byte(&p, 0); // minor version bytestream_put_be16(&p, 1); // headers packets without this one bytestream_put_buffer(&p, "fLaC", 4); bytestream_put_byte(&p, 0x00); // streaminfo bytestream_put_be24(&p, 34); bytestream_put_buffer(&p, extradata, 34); oggstream->header_len[1] = 1+3+4+strlen(vendor)+4; oggstream->header[1] = av_mallocz(oggstream->header_len[1]); p = oggstream->header[1]; bytestream_put_byte(&p, 0x84); // last metadata block and vorbis comment bytestream_put_be24(&p, oggstream->header_len[1] - 4); bytestream_put_le32(&p, strlen(vendor)); bytestream_put_buffer(&p, vendor, strlen(vendor)); bytestream_put_le32(&p, 0); // user comment list length return 0; }