[FFmpeg-devel] [PATCH 2/3] avcodec/libx265: add a qp option and apply the relevant global AVCodecContext settings to the encoder context

[James Almer]

Signed-off-by: James Almer <jamrial at gmail.com>
---
 doc/encoders.texi    | 22 ++++++++++++++++++++++
 libavcodec/libx265.c | 28 ++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/doc/encoders.texi b/doc/encoders.texi
index 673eaf6496..61e674cf96 100644
--- a/doc/encoders.texi
+++ b/doc/encoders.texi
@@ -2441,6 +2441,28 @@ Set profile restrictions.
 @item crf
 Set the quality for constant quality mode.
 
+ at item qp
+Set constant quantization rate control method parameter.
+
+ at item qmin
+Minimum quantizer scale.
+
+ at item qmax
+Maximum quantizer scale.
+
+ at item qdiff
+Maximum difference between quantizer scales.
+
+ at item qblur
+Quantizer curve blur
+
+ at item qcomp
+Quantizer curve compression factor
+
+ at item i_qfactor
+
+ at item b_qfactor
+
 @item forced-idr
 Normally, when forcing a I-frame type, the encoder can select any type
 of I-frame. This option forces it to choose an IDR-frame.
diff --git a/libavcodec/libx265.c b/libavcodec/libx265.c
index 508fade98b..581732d169 100644
--- a/libavcodec/libx265.c
+++ b/libavcodec/libx265.c
@@ -42,6 +42,7 @@ typedef struct libx265Context {
     const x265_api *api;
 
     float crf;
+    int   cqp;
     int   forced_idr;
     char *preset;
     char *tune;
@@ -223,11 +224,30 @@ static av_cold int libx265_encode_init(AVCodecContext *avctx)
             av_log(avctx, AV_LOG_ERROR, "Invalid crf: %2.2f.\n", ctx->crf);
             return AVERROR(EINVAL);
         }
+        ctx->params->rc.rateControlMode = X265_RC_CRF;
     } else if (avctx->bit_rate > 0) {
         ctx->params->rc.bitrate         = avctx->bit_rate / 1000;
         ctx->params->rc.rateControlMode = X265_RC_ABR;
+    } else if (ctx->cqp >= 0) {
+        ctx->params->rc.qp              = ctx->cqp;
+        ctx->params->rc.rateControlMode = X265_RC_CQP;
     }
 
+    if (avctx->qmin >= 0)
+        ctx->params->rc.qpMin = avctx->qmin;
+    if (avctx->qmax >= 0)
+        ctx->params->rc.qpMax = avctx->qmax;
+    if (avctx->max_qdiff >= 0)
+        ctx->params.rc.qpStep = avctx->max_qdiff;
+    if (avctx->qblur >= 0)
+        ctx->params->rc.qblur = avctx->qblur;
+    if (avctx->qcompress >= 0)
+        ctx->params->rc.qCompress = avctx->qcompress;
+    if (avctx->i_quant_factor > 0)
+        ctx->params->rc.ipFactor = 1 / fabs(avctx->i_quant_factor);
+    if (avctx->b_quant_factor > 0)
+        ctx->params->rc.pbFactor = avctx->b_quant_factor;
+
     ctx->params->rc.vbvBufferSize = avctx->rc_buffer_size / 1000;
     ctx->params->rc.vbvMaxBitrate = avctx->rc_max_rate    / 1000;
 
@@ -548,6 +568,7 @@ static av_cold void libx265_encode_init_csp(AVCodec *codec)
 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {
     { "crf",         "set the x265 crf",                                                            OFFSET(crf),       AV_OPT_TYPE_FLOAT,  { .dbl = -1 }, -1, FLT_MAX, VE },
+    { "qp",          "set the x265 qp",                                                             OFFSET(cqp),       AV_OPT_TYPE_INT,    { .i64 = -1 }, -1, INT_MAX, VE },
     { "forced-idr",  "if forcing keyframes, force them as IDR frames",                              OFFSET(forced_idr),AV_OPT_TYPE_BOOL,   { .i64 =  0 },  0,       1, VE },
     { "preset",      "set the x265 preset",                                                         OFFSET(preset),    AV_OPT_TYPE_STRING, { 0 }, 0, 0, VE },
     { "tune",        "set the x265 tune parameter",                                                 OFFSET(tune),      AV_OPT_TYPE_STRING, { 0 }, 0, 0, VE },
@@ -569,6 +590,13 @@ static const AVCodecDefault x265_defaults[] = {
     { "g", "-1" },
     { "keyint_min", "-1" },
     { "refs", "-1" },
+    { "qmin", "-1" },
+    { "qmax", "-1" },
+    { "qdiff", "-1" },
+    { "qblur", "-1" },
+    { "qcomp", "-1" },
+    { "i_qfactor", "-1" },
+    { "b_qfactor", "-1" },
     { NULL },
 };
 
-- 
2.24.1