[FFmpeg-devel] [PATCH 1/3] avcodec/decode: move processing discard samples to its own function
James Almer
jamrial at gmail.com
Sat Jul 8 22:41:17 EEST 2023
On 7/8/2023 4:38 PM, Andreas Rheinhardt wrote:
> 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)?
No, "git format-patch --diff-algorithm={minimal,patience,histogram}"
produces the same output.
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