+ ff_mdct_end(&ac->mdct_ltp);
+ return 0;
+}
+
+
+#define LOAS_SYNC_WORD 0x2b7 ///< 11 bits LOAS sync word
+
+struct LATMContext {
+ AACContext aac_ctx; ///< containing AACContext
+ int initialized; ///< initilized after a valid extradata was seen
+
+ // parser data
+ int audio_mux_version_A; ///< LATM syntax version
+ int frame_length_type; ///< 0/1 variable/fixed frame length
+ int frame_length; ///< frame length for fixed frame length
+};
+
+static inline uint32_t latm_get_value(GetBitContext *b)
+{
+ int length = get_bits(b, 2);
+
+ return get_bits_long(b, (length+1)*8);
+}
+
+static int latm_decode_audio_specific_config(struct LATMContext *latmctx,
+ GetBitContext *gb, int asclen)
+{
+ AACContext *ac = &latmctx->aac_ctx;
+ AVCodecContext *avctx = ac->avctx;
+ MPEG4AudioConfig m4ac = { 0 };
+ int config_start_bit = get_bits_count(gb);
+ int sync_extension = 0;
+ int bits_consumed, esize;
+
+ if (asclen) {
+ sync_extension = 1;
+ asclen = FFMIN(asclen, get_bits_left(gb));
+ } else
+ asclen = get_bits_left(gb);
+
+ if (config_start_bit % 8) {
+ av_log_missing_feature(latmctx->aac_ctx.avctx, "audio specific "
+ "config not byte aligned.\n", 1);
+ return AVERROR_INVALIDDATA;
+ }
+ if (asclen <= 0)
+ return AVERROR_INVALIDDATA;
+ bits_consumed = decode_audio_specific_config(NULL, avctx, &m4ac,
+ gb->buffer + (config_start_bit / 8),
+ asclen, sync_extension);
+
+ if (bits_consumed < 0)
+ return AVERROR_INVALIDDATA;
+
+ if (ac->oc[1].m4ac.sample_rate != m4ac.sample_rate ||
+ ac->oc[1].m4ac.chan_config != m4ac.chan_config) {
+
+ av_log(avctx, AV_LOG_INFO, "audio config changed\n");
+ latmctx->initialized = 0;
+
+ esize = (bits_consumed+7) / 8;
+
+ if (avctx->extradata_size < esize) {
+ av_free(avctx->extradata);
+ avctx->extradata = av_malloc(esize + FF_INPUT_BUFFER_PADDING_SIZE);
+ if (!avctx->extradata)
+ return AVERROR(ENOMEM);
+ }
+
+ avctx->extradata_size = esize;
+ memcpy(avctx->extradata, gb->buffer + (config_start_bit/8), esize);
+ memset(avctx->extradata+esize, 0, FF_INPUT_BUFFER_PADDING_SIZE);
+ }
+ skip_bits_long(gb, bits_consumed);
+
+ return bits_consumed;
+}
+
+static int read_stream_mux_config(struct LATMContext *latmctx,
+ GetBitContext *gb)
+{
+ int ret, audio_mux_version = get_bits(gb, 1);
+
+ latmctx->audio_mux_version_A = 0;
+ if (audio_mux_version)
+ latmctx->audio_mux_version_A = get_bits(gb, 1);
+
+ if (!latmctx->audio_mux_version_A) {
+
+ if (audio_mux_version)
+ latm_get_value(gb); // taraFullness
+
+ skip_bits(gb, 1); // allStreamSameTimeFraming
+ skip_bits(gb, 6); // numSubFrames
+ // numPrograms
+ if (get_bits(gb, 4)) { // numPrograms
+ av_log_missing_feature(latmctx->aac_ctx.avctx,
+ "multiple programs are not supported\n", 1);
+ return AVERROR_PATCHWELCOME;
+ }
+
+ // for each program (which there is only on in DVB)
+
+ // for each layer (which there is only on in DVB)
+ if (get_bits(gb, 3)) { // numLayer
+ av_log_missing_feature(latmctx->aac_ctx.avctx,
+ "multiple layers are not supported\n", 1);
+ return AVERROR_PATCHWELCOME;
+ }
+
+ // for all but first stream: use_same_config = get_bits(gb, 1);
+ if (!audio_mux_version) {
+ if ((ret = latm_decode_audio_specific_config(latmctx, gb, 0)) < 0)
+ return ret;
+ } else {
+ int ascLen = latm_get_value(gb);
+ if ((ret = latm_decode_audio_specific_config(latmctx, gb, ascLen)) < 0)
+ return ret;
+ ascLen -= ret;
+ skip_bits_long(gb, ascLen);
+ }
+
+ latmctx->frame_length_type = get_bits(gb, 3);
+ switch (latmctx->frame_length_type) {
+ case 0:
+ skip_bits(gb, 8); // latmBufferFullness
+ break;
+ case 1:
+ latmctx->frame_length = get_bits(gb, 9);
+ break;
+ case 3:
+ case 4:
+ case 5:
+ skip_bits(gb, 6); // CELP frame length table index
+ break;
+ case 6:
+ case 7:
+ skip_bits(gb, 1); // HVXC frame length table index
+ break;
+ }
+
+ if (get_bits(gb, 1)) { // other data
+ if (audio_mux_version) {
+ latm_get_value(gb); // other_data_bits
+ } else {
+ int esc;
+ do {
+ esc = get_bits(gb, 1);
+ skip_bits(gb, 8);
+ } while (esc);
+ }
+ }
+
+ if (get_bits(gb, 1)) // crc present
+ skip_bits(gb, 8); // config_crc
+ }
+
+ return 0;
+}
+
+static int read_payload_length_info(struct LATMContext *ctx, GetBitContext *gb)
+{
+ uint8_t tmp;
+
+ if (ctx->frame_length_type == 0) {
+ int mux_slot_length = 0;
+ do {
+ tmp = get_bits(gb, 8);
+ mux_slot_length += tmp;
+ } while (tmp == 255);
+ return mux_slot_length;
+ } else if (ctx->frame_length_type == 1) {
+ return ctx->frame_length;
+ } else if (ctx->frame_length_type == 3 ||
+ ctx->frame_length_type == 5 ||
+ ctx->frame_length_type == 7) {
+ skip_bits(gb, 2); // mux_slot_length_coded
+ }
+ return 0;
+}
+
+static int read_audio_mux_element(struct LATMContext *latmctx,
+ GetBitContext *gb)
+{
+ int err;
+ uint8_t use_same_mux = get_bits(gb, 1);
+ if (!use_same_mux) {
+ if ((err = read_stream_mux_config(latmctx, gb)) < 0)
+ return err;
+ } else if (!latmctx->aac_ctx.avctx->extradata) {
+ av_log(latmctx->aac_ctx.avctx, AV_LOG_DEBUG,
+ "no decoder config found\n");
+ return AVERROR(EAGAIN);
+ }
+ if (latmctx->audio_mux_version_A == 0) {
+ int mux_slot_length_bytes = read_payload_length_info(latmctx, gb);
+ if (mux_slot_length_bytes * 8 > get_bits_left(gb)) {
+ av_log(latmctx->aac_ctx.avctx, AV_LOG_ERROR, "incomplete frame\n");
+ return AVERROR_INVALIDDATA;
+ } else if (mux_slot_length_bytes * 8 + 256 < get_bits_left(gb)) {
+ av_log(latmctx->aac_ctx.avctx, AV_LOG_ERROR,
+ "frame length mismatch %d << %d\n",
+ mux_slot_length_bytes * 8, get_bits_left(gb));
+ return AVERROR_INVALIDDATA;
+ }
+ }