[FFmpeg-devel] [PATCH 1/3] avcodec/decode: move processing discard samples to its own function
Andreas Rheinhardt
andreas.rheinhardt at outlook.com
Sat Jul 8 22:38:22 EEST 2023
James Almer:
> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
> libavcodec/decode.c | 182 +++++++++++++++++++++++---------------------
> 1 file changed, 94 insertions(+), 88 deletions(-)
>
> diff --git a/libavcodec/decode.c b/libavcodec/decode.c
> index 269633ce10..793ab975f6 100644
> --- a/libavcodec/decode.c
> +++ b/libavcodec/decode.c
> @@ -289,69 +289,14 @@ static int64_t guess_correct_pts(AVCodecContext *ctx,
> return pts;
> }
>
> -/*
> - * The core of the receive_frame_wrapper for the decoders implementing
> - * the simple API. Certain decoders might consume partial packets without
> - * returning any output, so this function needs to be called in a loop until it
> - * returns EAGAIN.
> - **/
> -static inline int decode_simple_internal(AVCodecContext *avctx, AVFrame *frame, int64_t *discarded_samples)
> +static int discard_samples(AVCodecContext *avctx, AVFrame *frame, int64_t *discarded_samples)
> {
> - AVCodecInternal *avci = avctx->internal;
> - AVPacket *const pkt = avci->in_pkt;
> - const FFCodec *const codec = ffcodec(avctx->codec);
> - int got_frame, actual_got_frame;
> - int ret;
> -
> - if (!pkt->data && !avci->draining) {
> - av_packet_unref(pkt);
> - ret = ff_decode_get_packet(avctx, pkt);
> - if (ret < 0 && ret != AVERROR_EOF)
> - return ret;
> - }
> -
> - // Some codecs (at least wma lossless) will crash when feeding drain packets
> - // after EOF was signaled.
> - if (avci->draining_done)
> - return AVERROR_EOF;
> -
> - if (!pkt->data &&
> - !(avctx->codec->capabilities & AV_CODEC_CAP_DELAY ||
> - avctx->active_thread_type & FF_THREAD_FRAME))
> - return AVERROR_EOF;
> -
> - got_frame = 0;
> -
> - if (HAVE_THREADS && avctx->active_thread_type & FF_THREAD_FRAME) {
> - ret = ff_thread_decode_frame(avctx, frame, &got_frame, pkt);
> - } else {
> - ret = codec->cb.decode(avctx, frame, &got_frame, pkt);
> -
> - if (!(codec->caps_internal & FF_CODEC_CAP_SETS_PKT_DTS))
> - frame->pkt_dts = pkt->dts;
> - if (avctx->codec->type == AVMEDIA_TYPE_VIDEO) {
> -#if FF_API_FRAME_PKT
> -FF_DISABLE_DEPRECATION_WARNINGS
> - if(!avctx->has_b_frames)
> - frame->pkt_pos = pkt->pos;
> -FF_ENABLE_DEPRECATION_WARNINGS
> -#endif
> - //FIXME these should be under if(!avctx->has_b_frames)
> - /* get_buffer is supposed to set frame parameters */
> - if (!(avctx->codec->capabilities & AV_CODEC_CAP_DR1)) {
> - if (!frame->sample_aspect_ratio.num) frame->sample_aspect_ratio = avctx->sample_aspect_ratio;
> - if (!frame->width) frame->width = avctx->width;
> - if (!frame->height) frame->height = avctx->height;
> - if (frame->format == AV_PIX_FMT_NONE) frame->format = avctx->pix_fmt;
> - }
> - }
> - }
> - emms_c();
> - actual_got_frame = got_frame;
> + AVCodecInternal *avci = avctx->internal;
> + int ret = 0;
>
> if (avctx->codec->type == AVMEDIA_TYPE_VIDEO) {
> if (frame->flags & AV_FRAME_FLAG_DISCARD)
> - got_frame = 0;
> + ret = AVERROR(EAGAIN);
> } else if (avctx->codec->type == AVMEDIA_TYPE_AUDIO) {
> uint8_t *side;
> size_t side_size;
> @@ -359,16 +304,10 @@ FF_ENABLE_DEPRECATION_WARNINGS
> uint8_t skip_reason = 0;
> uint8_t discard_reason = 0;
>
> - if (ret >= 0 && got_frame) {
> if (frame->format == AV_SAMPLE_FMT_NONE)
> frame->format = avctx->sample_fmt;
> - if (!frame->ch_layout.nb_channels) {
> - int ret2 = av_channel_layout_copy(&frame->ch_layout, &avctx->ch_layout);
> - if (ret2 < 0) {
> - ret = ret2;
> - got_frame = 0;
> - }
> - }
> + if (!frame->ch_layout.nb_channels)
> + ret = av_channel_layout_copy(&frame->ch_layout, &avctx->ch_layout);
> #if FF_API_OLD_CHANNEL_LAYOUT
> FF_DISABLE_DEPRECATION_WARNINGS
> if (!frame->channel_layout)
> @@ -380,7 +319,6 @@ FF_ENABLE_DEPRECATION_WARNINGS
> #endif
> if (!frame->sample_rate)
> frame->sample_rate = avctx->sample_rate;
> - }
>
> side= av_packet_get_side_data(avci->last_pkt_props, AV_PKT_DATA_SKIP_SAMPLES, &side_size);
> if(side && side_size>=10) {
> @@ -393,21 +331,21 @@ FF_ENABLE_DEPRECATION_WARNINGS
> discard_reason = AV_RL8(side + 9);
> }
>
> - if ((frame->flags & AV_FRAME_FLAG_DISCARD) && got_frame &&
> + if ((frame->flags & AV_FRAME_FLAG_DISCARD) && !ret &&
> !(avctx->flags2 & AV_CODEC_FLAG2_SKIP_MANUAL)) {
> avci->skip_samples = FFMAX(0, avci->skip_samples - frame->nb_samples);
> - got_frame = 0;
> *discarded_samples += frame->nb_samples;
> + ret = AVERROR(EAGAIN);
> }
>
> - if (avci->skip_samples > 0 && got_frame &&
> + if (avci->skip_samples > 0 && !ret &&
> !(avctx->flags2 & AV_CODEC_FLAG2_SKIP_MANUAL)) {
> if(frame->nb_samples <= avci->skip_samples){
> - got_frame = 0;
> *discarded_samples += frame->nb_samples;
> avci->skip_samples -= frame->nb_samples;
> av_log(avctx, AV_LOG_DEBUG, "skip whole frame, skip left: %d\n",
> avci->skip_samples);
> + ret = AVERROR(EAGAIN);
> } else {
> av_samples_copy(frame->extended_data, frame->extended_data, 0, avci->skip_samples,
> frame->nb_samples - avci->skip_samples, avctx->ch_layout.nb_channels, frame->format);
> @@ -432,11 +370,11 @@ FF_ENABLE_DEPRECATION_WARNINGS
> }
> }
>
> - if (discard_padding > 0 && discard_padding <= frame->nb_samples && got_frame &&
> + if (discard_padding > 0 && discard_padding <= frame->nb_samples && !ret &&
> !(avctx->flags2 & AV_CODEC_FLAG2_SKIP_MANUAL)) {
> if (discard_padding == frame->nb_samples) {
> *discarded_samples += frame->nb_samples;
> - got_frame = 0;
> + ret = AVERROR(EAGAIN);
> } else {
> if(avctx->pkt_timebase.num && avctx->sample_rate) {
> int64_t diff_ts = av_rescale_q(frame->nb_samples - discard_padding,
> @@ -452,7 +390,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
> }
> }
>
> - if ((avctx->flags2 & AV_CODEC_FLAG2_SKIP_MANUAL) && got_frame) {
> + if ((avctx->flags2 & AV_CODEC_FLAG2_SKIP_MANUAL) && !ret) {
> AVFrameSideData *fside = av_frame_new_side_data(frame, AV_FRAME_DATA_SKIP_SAMPLES, 10);
> if (fside) {
> AV_WL32(fside->data, avci->skip_samples);
> @@ -464,15 +402,88 @@ FF_ENABLE_DEPRECATION_WARNINGS
> }
> }
>
> - if (!got_frame)
> + return ret;
> +}
> +
> +/*
> + * The core of the receive_frame_wrapper for the decoders implementing
> + * the simple API. Certain decoders might consume partial packets without
> + * returning any output, so this function needs to be called in a loop until it
> + * returns EAGAIN.
> + **/
> +static inline int decode_simple_internal(AVCodecContext *avctx, AVFrame *frame, int64_t *discarded_samples)
> +{
> + AVCodecInternal *avci = avctx->internal;
> + AVPacket *const pkt = avci->in_pkt;
> + const FFCodec *const codec = ffcodec(avctx->codec);
> + int got_frame;
> + int consumed, ret;
> +
> + if (!pkt->data && !avci->draining) {
> + av_packet_unref(pkt);
> + ret = ff_decode_get_packet(avctx, pkt);
> + if (ret < 0 && ret != AVERROR_EOF)
> + return ret;
> + }
> +
> + // Some codecs (at least wma lossless) will crash when feeding drain packets
> + // after EOF was signaled.
> + if (avci->draining_done)
> + return AVERROR_EOF;
> +
> + if (!pkt->data &&
> + !(avctx->codec->capabilities & AV_CODEC_CAP_DELAY ||
> + avctx->active_thread_type & FF_THREAD_FRAME))
> + return AVERROR_EOF;
> +
> + got_frame = 0;
> +
> + if (HAVE_THREADS && avctx->active_thread_type & FF_THREAD_FRAME) {
> + consumed = ff_thread_decode_frame(avctx, frame, &got_frame, pkt);
> + } else {
> + consumed = codec->cb.decode(avctx, frame, &got_frame, pkt);
> +
> + if (!(codec->caps_internal & FF_CODEC_CAP_SETS_PKT_DTS))
> + frame->pkt_dts = pkt->dts;
> + if (avctx->codec->type == AVMEDIA_TYPE_VIDEO) {
> +#if FF_API_FRAME_PKT
> +FF_DISABLE_DEPRECATION_WARNINGS
> + if(!avctx->has_b_frames)
> + frame->pkt_pos = pkt->pos;
> +FF_ENABLE_DEPRECATION_WARNINGS
> +#endif
> + //FIXME these should be under if(!avctx->has_b_frames)
> + /* get_buffer is supposed to set frame parameters */
> + if (!(avctx->codec->capabilities & AV_CODEC_CAP_DR1)) {
> + if (!frame->sample_aspect_ratio.num) frame->sample_aspect_ratio = avctx->sample_aspect_ratio;
> + if (!frame->width) frame->width = avctx->width;
> + if (!frame->height) frame->height = avctx->height;
> + if (frame->format == AV_PIX_FMT_NONE) frame->format = avctx->pix_fmt;
> + }
> + }
> + }
> + emms_c();
> +
> + if (got_frame)
> + ret = discard_samples(avctx, frame, discarded_samples);
> + else
> + ret = AVERROR(EAGAIN);
> +
> + if (consumed < 0)
> + ret = consumed;
> + if (consumed >= 0 && avctx->codec->type == AVMEDIA_TYPE_VIDEO)
> + consumed = pkt->size;
> +
> + if (!got_frame || ret == AVERROR(EAGAIN))
> av_frame_unref(frame);
>
> - if (ret >= 0 && avctx->codec->type == AVMEDIA_TYPE_VIDEO)
> - ret = pkt->size;
> + if (!ret)
> + av_assert0(frame->buf[0]);
> + if (ret == AVERROR(EAGAIN))
> + ret = 0;
>
> - /* do not stop draining when actual_got_frame != 0 or ret < 0 */
> - /* got_frame == 0 but actual_got_frame != 0 when frame is discarded */
> - if (avci->draining && !actual_got_frame) {
> + /* do not stop draining when got_frame != 0 or ret < 0 */
> + if (avci->draining && !got_frame) {
> if (ret < 0) {
> /* prevent infinite loop if a decoder wrongly always return error on draining */
> /* reasonable nb_errors_max = maximum b frames + thread count */
> @@ -490,11 +501,9 @@ FF_ENABLE_DEPRECATION_WARNINGS
> }
> }
>
> - if (ret >= pkt->size || ret < 0) {
> + if (consumed >= pkt->size || ret < 0) {
> av_packet_unref(pkt);
> } else {
> - int consumed = ret;
> -
> pkt->data += consumed;
> pkt->size -= consumed;
> pkt->pts = AV_NOPTS_VALUE;
> @@ -509,10 +518,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
> }
> }
>
> - if (got_frame)
> - av_assert0(frame->buf[0]);
> -
> - return ret < 0 ? ret : 0;
> + return ret;
> }
>
> #if CONFIG_LCMS2
Would using --diff-algorithm=minimal (or patience or histogram) produce
a more readable diff (i.e. one where the code that ends up in
discard_samples() is moved instead of everything except it)?
- Andreas
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