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
}
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;
av_log(avctx, AV_LOG_WARNING, "failed to clear buffer when flushing\n");
}
-AVCodec ff_libfdk_aac_decoder = {
+const AVCodec ff_libfdk_aac_decoder = {
.name = "libfdk_aac",
.long_name = NULL_IF_CONFIG_SMALL("Fraunhofer FDK AAC"),
.type = AVMEDIA_TYPE_AUDIO,