diff --git a/libavcodec/libopusdec.c b/libavcodec/libopusdec.c index 9b9a610343..8ec5bfc1ad 100644 --- a/libavcodec/libopusdec.c +++ b/libavcodec/libopusdec.c @@ -45,6 +45,8 @@ struct libopus_context { #ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST int apply_phase_inv; #endif + int decode_fec; + int64_t expected_next_pts; }; #define OPUS_HEAD_SIZE 19 @@ -141,6 +143,8 @@ static av_cold int libopus_decode_init(AVCodecContext *avc) /* Decoder delay (in samples) at 48kHz */ avc->delay = avc->internal->skip_samples = opus->pre_skip; + opus->expected_next_pts = AV_NOPTS_VALUE; + return 0; } @@ -161,27 +165,82 @@ static int libopus_decode(AVCodecContext *avc, AVFrame *frame, int *got_frame_ptr, AVPacket *pkt) { struct libopus_context *opus = avc->priv_data; - int ret, nb_samples; + uint8_t *outptr; + int ret, nb_samples = 0, nb_lost_samples = 0, nb_samples_left; + + // If FEC is enabled, calculate number of lost samples + if (opus->decode_fec && + opus->expected_next_pts != AV_NOPTS_VALUE && + pkt->pts != AV_NOPTS_VALUE && + pkt->pts != opus->expected_next_pts) { + // Cap at recovering 120 ms of lost audio. + nb_lost_samples = pkt->pts - opus->expected_next_pts; + nb_lost_samples = FFMIN(nb_lost_samples, MAX_FRAME_SIZE); + } - frame->nb_samples = MAX_FRAME_SIZE; + frame->nb_samples = MAX_FRAME_SIZE + nb_lost_samples; if ((ret = ff_get_buffer(avc, frame, 0)) < 0) return ret; + outptr = frame->data[0]; + nb_samples_left = frame->nb_samples; + + if (opus->decode_fec && nb_lost_samples) { + // Try to recover the lost samples with FEC data from this one. + // If there's no FEC data, the decoder will do loss concealment instead. + if (avc->sample_fmt == AV_SAMPLE_FMT_S16) + nb_samples = opus_multistream_decode(opus->dec, pkt->data, pkt->size, + (opus_int16 *)outptr, + nb_lost_samples, 1); + else + nb_samples = opus_multistream_decode_float(opus->dec, pkt->data, pkt->size, + (float *)outptr, + nb_lost_samples, 1); + + if (nb_samples < 0) { + av_log(avc, AV_LOG_ERROR, "Decoding error: %s\n", + opus_strerror(nb_samples)); + return ff_opus_error_to_averror(nb_samples); + } + + av_log(avc, AV_LOG_WARNING, "Recovered %d samples with FEC/PLC\n", + nb_samples); + + outptr += nb_samples * avc->channels * av_get_bytes_per_sample(avc->sample_fmt); + nb_samples_l