+struct eac3_info {
+ AVPacket pkt;
+ uint8_t ec3_done;
+ uint8_t num_blocks;
+
+ /* Layout of the EC3SpecificBox */
+ /* maximum bitrate */
+ uint16_t data_rate;
+ /* number of independent substreams */
+ uint8_t num_ind_sub;
+ struct {
+ /* sample rate code (see ff_ac3_sample_rate_tab) 2 bits */
+ uint8_t fscod;
+ /* bit stream identification 5 bits */
+ uint8_t bsid;
+ /* one bit reserved */
+ /* audio service mixing (not supported yet) 1 bit */
+ /* bit stream mode 3 bits */
+ uint8_t bsmod;
+ /* audio coding mode 3 bits */
+ uint8_t acmod;
+ /* sub woofer on 1 bit */
+ uint8_t lfeon;
+ /* 3 bits reserved */
+ /* number of dependent substreams associated with this substream 4 bits */
+ uint8_t num_dep_sub;
+ /* channel locations of the dependent substream(s), if any, 9 bits */
+ uint16_t chan_loc;
+ /* if there is no dependent substream, then one bit reserved instead */
+ } substream[1]; /* TODO: support 8 independent substreams */
+};
+
+static int handle_eac3(MOVMuxContext *mov, AVPacket *pkt, MOVTrack *track)
+{
+ GetBitContext gbc;
+ AC3HeaderInfo tmp, *hdr = &tmp;
+ struct eac3_info *info;
+ int num_blocks;
+
+ if (!track->eac3_priv && !(track->eac3_priv = av_mallocz(sizeof(*info))))
+ return AVERROR(ENOMEM);
+ info = track->eac3_priv;
+
+ init_get_bits(&gbc, pkt->data, pkt->size * 8);
+ if (avpriv_ac3_parse_header2(&gbc, &hdr) < 0) {
+ /* drop the packets until we see a good one */
+ if (!track->entry) {
+ av_log(mov, AV_LOG_WARNING, "Dropping invalid packet from start of the stream\n");
+ return 0;
+ }
+ return AVERROR_INVALIDDATA;
+ }
+
+ info->data_rate = FFMAX(info->data_rate, hdr->bit_rate / 1000);
+ num_blocks = hdr->num_blocks;
+
+ if (!info->ec3_done) {
+ /* AC-3 substream must be the first one */
+ if (hdr->bitstream_id <= 10 && hdr->substreamid != 0)
+ return AVERROR(EINVAL);
+
+ /* this should always be the case, given that our AC-3 parser
+ * concatenates dependent frames to their independent parent */
+ if (hdr->frame_type == EAC3_FRAME_TYPE_INDEPENDENT) {
+ /* substream ids must be incremental */
+ if (hdr->substreamid > info->num_ind_sub + 1)
+ return AVERROR(EINVAL);
+
+ if (hdr->substreamid == info->num_ind_sub + 1) {
+ //info->num_ind_sub++;
+ avpriv_request_sample(track->enc, "Multiple independent substreams");
+ return AVERROR_PATCHWELCOME;
+ } else if (hdr->substreamid < info->num_ind_sub ||
+ hdr->substreamid == 0 && info->substream[0].bsid) {
+ info->ec3_done = 1;
+ goto concatenate;
+ }
+ }
+
+ /* fill the info needed for the "dec3" atom */
+ info->substream[hdr->substreamid].fscod = hdr->sr_code;
+ info->substream[hdr->substreamid].bsid = hdr->bitstream_id;
+ info->substream[hdr->substreamid].bsmod = hdr->bitstream_mode;
+ info->substream[hdr->substreamid].acmod = hdr->channel_mode;
+ info->substream[hdr->substreamid].lfeon = hdr->lfe_on;
+
+ /* Parse dependent substream(s), if any */
+ if (pkt->size != hdr->frame_size) {
+ int cumul_size = hdr->frame_size;
+ int parent = hdr->substreamid;
+
+ while (cumul_size != pkt->size) {
+ int i;
+ init_get_bits(&gbc, pkt->data + cumul_size, (pkt->size - cumul_size) * 8);
+ if (avpriv_ac3_parse_header2(&gbc, &hdr) < 0)
+ return AVERROR_INVALIDDATA;
+ if (hdr->frame_type != EAC3_FRAME_TYPE_DEPENDENT)
+ return AVERROR(EINVAL);
+ cumul_size += hdr->frame_size;
+ info->substream[parent].num_dep_sub++;
+
+ /* header is parsed up to lfeon, but custom channel map may be needed */
+ /* skip bsid */
+ skip_bits(&gbc, 5);
+ /* skip volume control params */
+ for (i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
+ skip_bits(&gbc, 5); // skip dialog normalization
+ if (get_bits1(&gbc)) {
+ skip_bits(&gbc, 8); // skip compression gain word
+ }
+ }
+ /* get the dependent stream channel map, if exists */
+ if (get_bits1(&gbc))
+ info->substream[parent].chan_loc |= (get_bits(&gbc, 16) >> 5) & 0x1f;
+ else
+ info->substream[parent].chan_loc |= hdr->channel_mode;
+ }
+ }
+ }
+
+concatenate:
+ if (!info->num_blocks && num_blocks == 6)
+ return pkt->size;
+ else if (info->num_blocks + num_blocks > 6)
+ return AVERROR_INVALIDDATA;
+
+ if (!info->num_blocks) {
+ int ret;
+ if ((ret = av_copy_packet(&info->pkt, pkt)) < 0)
+ return ret;
+ info->num_blocks = num_blocks;
+ return 0;
+ } else {
+ int ret;
+ if ((ret = av_grow_packet(&info->pkt, pkt->size)) < 0)
+ return ret;
+ memcpy(info->pkt.data + info->pkt.size - pkt->size, pkt->data, pkt->size);
+ info->num_blocks += num_blocks;
+ info->pkt.duration += pkt->duration;
+ if ((ret = av_copy_packet_side_data(&info->pkt, pkt)) < 0)
+ return ret;
+ if (info->num_blocks != 6)
+ return 0;
+ av_free_packet(pkt);
+ if ((ret = av_copy_packet(pkt, &info->pkt)) < 0)
+ return ret;
+ av_free_packet(&info->pkt);
+ info->num_blocks = 0;
+ }
+
+ return pkt->size;
+}
+
+static int mov_write_eac3_tag(AVIOContext *pb, MOVTrack *track)
+{
+ PutBitContext pbc;
+ uint8_t *buf;
+ struct eac3_info *info;
+ int size, i;
+
+ if (!track->eac3_priv)
+ return AVERROR(EINVAL);
+
+ info = track->eac3_priv;
+ size = 2 + 4 * (info->num_ind_sub + 1);
+ buf = av_malloc(size);
+ if (!buf) {
+ size = AVERROR(ENOMEM);
+ goto end;
+ }
+
+ init_put_bits(&pbc, buf, size);
+ put_bits(&pbc, 13, info->data_rate);
+ put_bits(&pbc, 3, info->num_ind_sub);
+ for (i = 0; i <= info->num_ind_sub; i++) {
+ put_bits(&pbc, 2, info->substream[i].fscod);
+ put_bits(&pbc, 5, info->substream[i].bsid);
+ put_bits(&pbc, 1, 0); /* reserved */
+ put_bits(&pbc, 1, 0); /* asvc */
+ put_bits(&pbc, 3, info->substream[i].bsmod);
+ put_bits(&pbc, 3, info->substream[i].acmod);
+ put_bits(&pbc, 1, info->substream[i].lfeon);
+ put_bits(&pbc, 5, 0); /* reserved */
+ put_bits(&pbc, 4, info->substream[i].num_dep_sub);
+ if (!info->substream[i].num_dep_sub) {
+ put_bits(&pbc, 1, 0); /* reserved */
+ size--;
+ } else {
+ put_bits(&pbc, 9, info->substream[i].chan_loc);
+ }
+ }
+ flush_put_bits(&pbc);
+
+ avio_wb32(pb, size + 8);
+ ffio_wfourcc(pb, "dec3");
+ avio_write(pb, buf, size);
+
+ av_free(buf);
+
+end:
+ av_free_packet(&info->pkt);
+ av_freep(&track->eac3_priv);
+
+ return size;
+}
+