lavc: add codec parameters API

This API is intended to allow passing around codec parameters without
using full AVCodecContext (which also contains codec options and
encoder/decoder state).

1 files changed, 152 insertions, 0 deletions

diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 94ec1e8047..86a67e1672 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -2440,3 +2440,155 @@ AVCPBProperties *ff_add_cpb_side_data(AVCodecContext *avctx)
 
     return props;
 }
+
+static void codec_parameters_reset(AVCodecParameters *par)
+{
+    av_freep(&par->extradata);
+
+    memset(par, 0, sizeof(*par));
+
+    par->codec_type          = AVMEDIA_TYPE_UNKNOWN;
+    par->codec_id            = AV_CODEC_ID_NONE;
+    par->format              = -1;
+    par->field_order         = AV_FIELD_UNKNOWN;
+    par->color_range         = AVCOL_RANGE_UNSPECIFIED;
+    par->color_primaries     = AVCOL_PRI_UNSPECIFIED;
+    par->color_trc           = AVCOL_TRC_UNSPECIFIED;
+    par->color_space         = AVCOL_SPC_UNSPECIFIED;
+    par->chroma_location     = AVCHROMA_LOC_UNSPECIFIED;
+    par->sample_aspect_ratio = (AVRational){ 0, 1 };
+}
+
+AVCodecParameters *avcodec_parameters_alloc(void)
+{
+    AVCodecParameters *par = av_mallocz(sizeof(*par));
+
+    if (!par)
+        return NULL;
+    codec_parameters_reset(par);
+    return par;
+}
+
+void avcodec_parameters_free(AVCodecParameters **ppar)
+{
+    AVCodecParameters *par = *ppar;
+
+    if (!par)
+        return;
+    codec_parameters_reset(par);
+
+    av_freep(ppar);
+}
+
+int avcodec_parameters_copy(AVCodecParameters *dst, const AVCodecParameters *src)
+{
+    codec_parameters_reset(dst);
+    memcpy(dst, src, sizeof(*dst));
+
+    dst->extradata      = NULL;
+    dst->extradata_size = 0;
+    if (src->extradata) {
+        dst->extradata = av_mallocz(src->extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
+        if (!dst->extradata)
+            return AVERROR(ENOMEM);
+        memcpy(dst->extradata, src->extradata, src->extradata_size);
+        dst->extradata_size = src->extradata_size;
+    }
+
+    return 0;
+}
+
+int avcodec_parameters_from_context(AVCodecParameters *par,
+                                    const AVCodecContext *codec)
+{
+    codec_parameters_reset(par);
+
+    par->codec_type = codec->codec_type;
+    par->codec_id   = codec->codec_id;
+    par->codec_tag  = codec->codec_tag;
+
+    par->bit_rate              = codec->bit_rate;
+    par->bits_per_coded_sample = codec->bits_per_coded_sample;
+    par->profile               = codec->profile;
+    par->level                 = codec->level;
+
+    switch (par->codec_type) {
+    case AVMEDIA_TYPE_VIDEO:
+        par->format              = codec->pix_fmt;
+        par->width               = codec->width;
+        par->height              = codec->height;
+        par->field_order         = codec->field_order;
+        par->color_range         = codec->color_range;
+        par->color_primaries     = codec->color_primaries;
+        par->color_trc           = codec->color_trc;
+        par->color_space         = codec->colorspace;
+        par->chroma_location     = codec->chroma_sample_location;
+        par->sample_aspect_ratio = codec->sample_aspect_ratio;
+        break;
+    case AVMEDIA_TYPE_AUDIO:
+        par->format          = codec->sample_fmt;
+        par->channel_layout  = codec->channel_layout;
+        par->channels        = codec->channels;
+        par->sample_rate     = codec->sample_rate;
+        par->block_align     = codec->block_align;
+        par->initial_padding = codec->initial_padding;
+        break;
+    }
+
+    if (codec->extradata) {
+        par->extradata = av_mallocz(codec->extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
+        if (!par->extradata)
+            return AVERROR(ENOMEM);
+        memcpy(par->extradata, codec->extradata, codec->extradata_size);
+        par->extradata_size = codec->extradata_size;
+    }
+
+    return 0;
+}
+
+int avcodec_parameters_to_context(AVCodecContext *codec,
+                                  const AVCodecParameters *par)
+{
+    codec->codec_type = par->codec_type;
+    codec->codec_id   = par->codec_id;
+    codec->codec_tag  = par->codec_tag;
+
+    codec->bit_rate              = par->bit_rate;
+    codec->bits_per_coded_sample = par->bits_per_coded_sample;
+    codec->profile               = par->profile;
+    codec->level                 = par->level;
+
+    switch (par->codec_type) {
+    case AVMEDIA_TYPE_VIDEO:
+        codec->pix_fmt                = par->format;
+        codec->width                  = par->width;
+        codec->height                 = par->height;
+        codec->field_order            = par->field_order;
+        codec->color_range            = par->color_range;
+        codec->color_primaries        = par->color_primaries;
+        codec->color_trc              = par->color_trc;
+        codec->colorspace             = par->color_space;
+        codec->chroma_sample_location = par->chroma_location;
+        codec->sample_aspect_ratio    = par->sample_aspect_ratio;
+        break;
+    case AVMEDIA_TYPE_AUDIO:
+        codec->sample_fmt      = par->format;
+        codec->channel_layout  = par->channel_layout;
+        codec->channels        = par->channels;
+        codec->sample_rate     = par->sample_rate;
+        codec->block_align     = par->block_align;
+        codec->initial_padding = par->initial_padding;
+        break;
+    }
+
+    if (par->extradata) {
+        av_freep(&codec->extradata);
+        codec->extradata = av_mallocz(par->extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
+        if (!codec->extradata)
+            return AVERROR(ENOMEM);
+        memcpy(codec->extradata, par->extradata, par->extradata_size);
+        codec->extradata_size = par->extradata_size;
+    }
+
+    return 0;
+}