[FFmpeg-devel] [PATCH 5/8] lavc/encode: add an encoder-specific get_buffer() variant
James Almer
jamrial at gmail.com
Wed Mar 23 18:26:48 EET 2022
On 3/23/2022 12:57 PM, Anton Khirnov wrote:
> Several encoders (roqvideo, svq1, snow, and the mpegvideo family)
> currently call ff_get_buffer(). However this function is written
> assuming it is called by a decoder. Though nothing has been obviously
> broken by this until now, this may change in the future.
>
> To avoid potential future issues, introduce a simple encode-specific
> wrapper around avcodec_default_get_buffer2() and enforce its use in
> encoders.
> ---
> libavcodec/decode.c | 2 ++
> libavcodec/encode.c | 34 ++++++++++++++++++++++++++++++++++
> libavcodec/encode.h | 5 +++++
> libavcodec/mpegpicture.c | 16 +++++++++-------
> libavcodec/roqvideoenc.c | 4 ++--
> libavcodec/snow.c | 8 ++++++--
> libavcodec/svq1enc.c | 4 ++--
> 7 files changed, 60 insertions(+), 13 deletions(-)
>
> diff --git a/libavcodec/decode.c b/libavcodec/decode.c
> index fffad5f700..3733e6d4b8 100644
> --- a/libavcodec/decode.c
> +++ b/libavcodec/decode.c
> @@ -1405,6 +1405,8 @@ int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
> int override_dimensions = 1;
> int ret;
>
> + av_assert0(av_codec_is_decoder(avctx->codec));
> +
> if (avctx->codec_type == AVMEDIA_TYPE_VIDEO) {
> if ((unsigned)avctx->width > INT_MAX - STRIDE_ALIGN ||
> (ret = av_image_check_size2(FFALIGN(avctx->width, STRIDE_ALIGN), avctx->height, avctx->max_pixels, AV_PIX_FMT_NONE, 0, avctx)) < 0 || avctx->pix_fmt<0) {
> diff --git a/libavcodec/encode.c b/libavcodec/encode.c
> index 837ffaa40d..ec8d06d068 100644
> --- a/libavcodec/encode.c
> +++ b/libavcodec/encode.c
> @@ -572,3 +572,37 @@ FF_ENABLE_DEPRECATION_WARNINGS
>
> return 0;
> }
> +
> +int ff_encode_alloc_frame(AVCodecContext *avctx, AVFrame *frame)
> +{
> + int ret;
> +
> + switch (avctx->codec->type) {
> + case AVMEDIA_TYPE_VIDEO:
> + frame->format = avctx->pix_fmt;
> + if (frame->width <= 0 || frame->height <= 0) {
> + frame->width = FFMAX(avctx->width, avctx->coded_width);
> + frame->height = FFMAX(avctx->height, avctx->coded_height);
> + }
> +
> + break;
> + case AVMEDIA_TYPE_AUDIO:
> + frame->sample_rate = avctx->sample_rate;
> + frame->format = avctx->sample_fmt;
> + if (!frame->ch_layout.nb_channels) {
> + int ret = av_channel_layout_copy(&frame->ch_layout, &avctx->ch_layout);
Unnecessarily shadowing ret.
> + if (ret < 0)
> + return ret;
> + }
> + break;
> + }
> +
> + ret = avcodec_default_get_buffer2(avctx, frame, 0);
> + if (ret < 0) {
> + av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
> + av_frame_unref(frame);
> + return ret;
> + }
> +
> + return 0;
> +}
> diff --git a/libavcodec/encode.h b/libavcodec/encode.h
> index 97b3acf9df..b2536bf0f3 100644
> --- a/libavcodec/encode.h
> +++ b/libavcodec/encode.h
> @@ -44,6 +44,11 @@ int ff_encode_get_frame(AVCodecContext *avctx, AVFrame *frame);
> */
> int ff_get_encode_buffer(AVCodecContext *avctx, AVPacket *avpkt, int64_t size, int flags);
>
> +/**
> + * Allocate buffers for a frame. Encoder equivalent to ff_get_buffer().
> + */
> +int ff_encode_alloc_frame(AVCodecContext *avctx, AVFrame *frame);
> +
> /**
> * Check AVPacket size and allocate data.
> *
> diff --git a/libavcodec/mpegpicture.c b/libavcodec/mpegpicture.c
> index 681ccc2b82..aaa1df0bd8 100644
> --- a/libavcodec/mpegpicture.c
> +++ b/libavcodec/mpegpicture.c
> @@ -26,6 +26,7 @@
> #include "libavutil/imgutils.h"
>
> #include "avcodec.h"
> +#include "encode.h"
> #include "motion_est.h"
> #include "mpegpicture.h"
> #include "mpegutils.h"
> @@ -123,14 +124,15 @@ static int alloc_frame_buffer(AVCodecContext *avctx, Picture *pic,
> int r, ret;
>
> pic->tf.f = pic->f;
> - if (avctx->codec_id != AV_CODEC_ID_WMV3IMAGE &&
> - avctx->codec_id != AV_CODEC_ID_VC1IMAGE &&
> - avctx->codec_id != AV_CODEC_ID_MSS2) {
> - if (edges_needed) {
> - pic->f->width = avctx->width + 2 * EDGE_WIDTH;
> - pic->f->height = avctx->height + 2 * EDGE_WIDTH;
> - }
>
> + if (edges_needed) {
> + pic->f->width = avctx->width + 2 * EDGE_WIDTH;
> + pic->f->height = avctx->height + 2 * EDGE_WIDTH;
> +
> + r = ff_encode_alloc_frame(avctx, pic->f);
> + } else if (avctx->codec_id != AV_CODEC_ID_WMV3IMAGE &&
> + avctx->codec_id != AV_CODEC_ID_VC1IMAGE &&
> + avctx->codec_id != AV_CODEC_ID_MSS2) {
> r = ff_thread_get_ext_buffer(avctx, &pic->tf,
> pic->reference ? AV_GET_BUFFER_FLAG_REF : 0);
> } else {
> diff --git a/libavcodec/roqvideoenc.c b/libavcodec/roqvideoenc.c
> index ef7861088d..95db514140 100644
> --- a/libavcodec/roqvideoenc.c
> +++ b/libavcodec/roqvideoenc.c
> @@ -1081,8 +1081,8 @@ static int roq_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
> if (enc->first_frame) {
> /* Alloc memory for the reconstruction data (we must know the stride
> for that) */
> - if ((ret = ff_get_buffer(avctx, roq->current_frame, 0)) < 0 ||
> - (ret = ff_get_buffer(avctx, roq->last_frame, 0)) < 0)
> + if ((ret = ff_encode_alloc_frame(avctx, roq->current_frame)) < 0 ||
> + (ret = ff_encode_alloc_frame(avctx, roq->last_frame )) < 0)
> return ret;
>
> /* Before the first video frame, write a "video info" chunk */
> diff --git a/libavcodec/snow.c b/libavcodec/snow.c
> index 1224b95491..bc0d9a8983 100644
> --- a/libavcodec/snow.c
> +++ b/libavcodec/snow.c
> @@ -23,6 +23,7 @@
> #include "libavutil/opt.h"
> #include "libavutil/thread.h"
> #include "avcodec.h"
> +#include "encode.h"
> #include "me_cmp.h"
> #include "snow_dwt.h"
> #include "internal.h"
> @@ -76,8 +77,11 @@ int ff_snow_get_buffer(SnowContext *s, AVFrame *frame)
> if (edges_needed) {
> frame->width += 2 * EDGE_WIDTH;
> frame->height += 2 * EDGE_WIDTH;
> - }
> - if ((ret = ff_get_buffer(s->avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
> +
> + ret = ff_encode_alloc_frame(s->avctx, frame);
> + } else
> + ret = ff_get_buffer(s->avctx, frame, AV_GET_BUFFER_FLAG_REF);
> + if (ret < 0)
> return ret;
> if (edges_needed) {
> for (i = 0; frame->data[i]; i++) {
> diff --git a/libavcodec/svq1enc.c b/libavcodec/svq1enc.c
> index 706bc2e42e..cb0d0308fc 100644
> --- a/libavcodec/svq1enc.c
> +++ b/libavcodec/svq1enc.c
> @@ -595,12 +595,12 @@ static int svq1_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
> }
>
> if (!s->current_picture->data[0]) {
> - if ((ret = ff_get_buffer(avctx, s->current_picture, 0)) < 0) {
> + if ((ret = ff_encode_alloc_frame(avctx, s->current_picture)) < 0) {
> return ret;
> }
> }
> if (!s->last_picture->data[0]) {
> - ret = ff_get_buffer(avctx, s->last_picture, 0);
> + ret = ff_encode_alloc_frame(avctx, s->last_picture);
> if (ret < 0)
> return ret;
> }
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