diff options
Diffstat (limited to 'libavcodec/libfdk-aacdec.c')
| -rw-r--r-- | libavcodec/libfdk-aacdec.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/libavcodec/libfdk-aacdec.c b/libavcodec/libfdk-aacdec.c index ec7f236ce7..1a86dffe4b 100644 --- a/libavcodec/libfdk-aacdec.c +++ b/libavcodec/libfdk-aacdec.c @@ -76,8 +76,8 @@ static const AVOption fdk_aac_dec_options[] = { OFFSET(drc_boost), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 127, AD, NULL }, { "drc_cut", "Dynamic Range Control: attenuation factor, where [0] is none and [127] is max compression", OFFSET(drc_cut), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 127, AD, NULL }, - { "drc_level", "Dynamic Range Control: reference level, quantized to 0.25dB steps where [0] is 0dB and [127] is -31.75dB", - OFFSET(drc_level), AV_OPT_TYPE_INT, { .i64 = -1}, -1, 127, AD, NULL }, + { "drc_level", "Dynamic Range Control: reference level, quantized to 0.25dB steps where [0] is 0dB and [127] is -31.75dB, -1 for auto, and -2 for disabled", + OFFSET(drc_level), AV_OPT_TYPE_INT, { .i64 = -1}, -2, 127, AD, NULL }, { "drc_heavy", "Dynamic Range Control: heavy compression, where [1] is on (RF mode) and [0] is off", OFFSET(drc_heavy), AV_OPT_TYPE_INT, { .i64 = -1}, -1, 1, AD, NULL }, #if FDKDEC_VER_AT_LEAST(2, 5) // 2.5.10 @@ -299,6 +299,12 @@ static av_cold int fdk_aac_decode_init(AVCodecContext *avctx) } if (s->drc_level != -1) { + // This option defaults to -1, i.e. not calling + // aacDecoder_SetParam(AAC_DRC_REFERENCE_LEVEL) at all, which defaults + // to the level from DRC metadata, if available. The user can set + // -drc_level -2, which calls aacDecoder_SetParam( + // AAC_DRC_REFERENCE_LEVEL) with a negative value, which then + // explicitly disables the feature. if (aacDecoder_SetParam(s->handle, AAC_DRC_REFERENCE_LEVEL, s->drc_level) != AAC_DEC_OK) { av_log(avctx, AV_LOG_ERROR, "Unable to set DRC reference level in the decoder\n"); return AVERROR_UNKNOWN; |