On Mon, 25 Aug 2014 12:50:40 +0200, Janne Grunau <[email protected]> wrote:
> On 2014-08-24 13:00:11 +0000, Anton Khirnov wrote:
> > ---
> > libavcodec/avcodec.h | 145
> > +++++++++++++++++++++++++++++++++++++++++++++++++++
> > libavcodec/utils.c | 144
> > ++++++++++++++++++++++++++++++++++++++++++++++++++
> > 2 files changed, 289 insertions(+)
> >
> > diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
> > index c7fbed9..2a9c5ec 100644
> > --- a/libavcodec/avcodec.h
> > +++ b/libavcodec/avcodec.h
> > @@ -3091,6 +3091,109 @@ typedef struct AVSubtitle {
> > } AVSubtitle;
> >
> > /**
> > + * This struct describes the properties of an encoded stream.
> > + *
> > + * sizeof(AVCodecParameters) is not a part of the public ABI, this struct
> > must
> > + * be allocated with avcodec_parameters_alloc() and freed with
> > + * avcodec_parameters_free().
> > + */
> > +typedef struct AVCodecParameters {
> > + /**
> > + * General type of the encoded data.
> > + */
> > + enum AVMediaType codec_type;
> > + /**
> > + * Specific type of the encoded data (the codec used).
> > + */
> > + enum AVCodecID codec_id;
> > + /**
> > + * Additional information about the codec (corresponds to the AVI
> > FOURCC).
> > + */
>
> or wav TWOCC I think
>
Right, will fix.
> > + uint32_t codec_tag;
> > +
> > + /**
> > + * Extra binary data needed for initializing the decoder,
> > codec-dependent.
> > + *
> > + * Must be allocated with av_malloc() and will be freed by
> > + * avcodec_parameters_free(). The allocated size of extradata must be
> > at
> > + * least extradata_size + FF_MIN_BUFFER_SIZE, with the padding bytes
> > zeroed.
>
> FF_INPUT_BUFFER_PADDING_SIZE; 16kB padding would be ridiculous
>
Ditto.
> > + */
> > + uint8_t *extradata;
> > + /**
> > + * Size of the extradata content in bytes.
> > + */
> > + int extradata_size;
> > +
> > + /**
> > + * - video: the pixel format, the value corresponds to enum
> > AVPixelFormat.
> > + * - audio: the sample format, the value corresponds to enum
> > AVSampleFormat.
> > + */
> > + int format;
> > + /**
> > + * The average bitrate of the encoded data (in bits per second).
> > + */
> > + int bit_rate;
> > + int bits_per_coded_sample;
> > +
> > + /**
> > + * Video only. The dimensions of the video frame in pixels.
> > + */
> > + int width;
> > + int height;
> > +
> > + /**
> > + * Video only. The order of the fields in interlaced video.
> > + */
> > + enum AVFieldOrder field_order;
> > +
> > + /**
> > + * Video only. Additional colorspace characteristics.
> > + */
> > + enum AVColorRange color_range;
> > + enum AVColorPrimaries color_primaries;
> > + enum AVColorTransferCharacteristic color_trc;
> > + enum AVColorSpace color_space;
> > + enum AVChromaLocation chroma_location;
> > +
> > + /**
> > + * Audio only. The channel layout bitmask. May be 0 if the channel
> > layout is
> > + * unknown or unspecified, otherwise the number of bits set must be
> > equal to
> > + * the channels field.
> > + */
> > + uint64_t channel_layout;
> > + /**
> > + * Audio only. The number of audio channels.
> > + */
> > + int channels;
> > + /**
> > + * Audio only. The number of audio samples per second.
> > + */
> > + int sample_rate;
> > + /**
> > + * Audio only. The number of bytes per coded audio frame, required by
> > some
> > + * formats.
> > + *
> > + * Corresponds to nBlockAlign in WAVEFORMATEX.
> > + */
> > + int block_align;
> > +
> > + /**
> > + * Audio only. The amount of padding (in samples) inserted by the
> > encoder at
> > + * the beginning of the audio. I.e. this number of leading decoded
> > samples
> > + * must be discarded by the caller to get the original audio without
> > leading
> > + * padding.
> > + */
> > + int initial_padding;
> > + /**
> > + * Audio only. The amount of padding (in samples) appended by the
> > encoder to
> > + * the end of the audio. I.e. this number of decoded samples must be
> > + * discarded by the caller from the end of the stream to get the
> > original
> > + * audio without any trailing padding.
> > + */
> > + int trailing_padding;
> > +} AVCodecParameters;
>
> I wonder if it make sense to encapsulate the audio/video specific values
> in their own structs and embed an union of them. Probably too much
> effort for little gain though.
>
Considered it, but my conclusion was the same as yours.
> > +
> > +/**
> > * If c is NULL, returns the first registered codec,
> > * if c is non-NULL, returns the next registered codec after c,
> > * or NULL if c is the last one.
> > @@ -3188,6 +3291,48 @@ const AVClass *avcodec_get_class(void);
> > */
> > int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src);
> >
> > +/**
> > + * Allocate a new AVCodecParameters and set its fields to default values
> > + * (unknown/invalid/0). The returned struct must be freed with
> > + * avcodec_parameters_free().
> > + */
> > +AVCodecParameters *avcodec_parameters_alloc(void);
> > +
> > +/**
> > + * Free an AVCodecParameters instance and everything associated with it and
> > + * write NULL to the supplied pointer.
> > + */
> > +void avcodec_parameters_free(AVCodecParameters **par);
> > +
> > +/**
> > + * Copy the contents of src to dst. Any allocated fields in dst are freed
> > and
> > + * replaced with newly allocated duplicates of the corresponding fields in
> > src.
> > + *
> > + * @return >= 0 on success, a negative AVERROR code on failure.
> > + */
> > +int avcodec_parameters_copy(AVCodecParameters *dst, const
> > AVCodecParameters *src);
> > +
> > +/**
> > + * Fill the parameters struct based on the values from the supplied codec
> > + * context. Any allocated fields in par are freed and replaced with
> > duplicates
> > + * of the corresponding fields in codec.
> > + *
> > + * @return >= 0 on success, a negative AVERROR code on failure
> > + */
> > +int avcodec_parameters_from_context(AVCodecParameters *par,
> > + const AVCodecContext *codec);
> > +
> > +/**
> > + * Fill the codec context based on the values from the supplied codec
> > + * parameters. Any allocated fields in codec that have a corresponding
> > field in
> > + * par are freed and replaced with duplicates of the corresponding field
> > in par.
> > + * Fields in codec that do not have a counterpart in par are not touched.
> > + *
> > + * @return >= 0 on success, a negative AVERROR code on failure.
> > + */
> > +int avcodec_parameters_to_context(AVCodecContext *codec,
> > + const AVCodecParameters *par);
> > +
> > #if FF_API_AVFRAME_LAVC
> > /**
> > * @deprecated use av_frame_alloc()
> > diff --git a/libavcodec/utils.c b/libavcodec/utils.c
> > index e0f11d3..baa25eb 100644
> > --- a/libavcodec/utils.c
> > +++ b/libavcodec/utils.c
> > @@ -2418,3 +2418,147 @@ const uint8_t *avpriv_find_start_code(const uint8_t
> > *restrict p,
> >
> > return p + 4;
> > }
> > +
> > +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;
> > +}
> > +
> > +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 +
> > FF_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;
> > +
> > + 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;
> > + 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;
>
> AVCodecContext has no field initial_padding here, same problem in
> avcodec_parameters_to_context()
There's a patch on the ML adding it.
--
Anton Khirnov
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