[FFmpeg-devel] [PATCH] avcodec/libaomenc: remove one memcpy when queueing packets
Andreas Rheinhardt
andreas.rheinhardt at outlook.com
Thu Aug 25 19:29:11 EEST 2022
James Almer:
> Don't use an intermediary buffer. Achieve this by replacing FrameListData with
> a PacketList, and by allocating and populating every packet's payload before
> inserting them into the list.
>
> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
> libavcodec/libaomenc.c | 195 +++++++++++++++--------------------------
> 1 file changed, 70 insertions(+), 125 deletions(-)
>
> diff --git a/libavcodec/libaomenc.c b/libavcodec/libaomenc.c
> index 485f554165..f9476b3ddf 100644
> --- a/libavcodec/libaomenc.c
> +++ b/libavcodec/libaomenc.c
> @@ -38,6 +38,7 @@
>
> #include "av1.h"
> #include "avcodec.h"
> +#include "bytestream.h"
> #include "bsf.h"
> #include "codec_internal.h"
> #include "encode.h"
> @@ -46,24 +47,6 @@
> #include "packet_internal.h"
> #include "profiles.h"
>
> -/*
> - * Portion of struct aom_codec_cx_pkt from aom_encoder.h.
> - * One encoded frame returned from the library.
> - */
> -struct FrameListData {
> - void *buf; /**< compressed data buffer */
> - size_t sz; /**< length of compressed data */
> - int64_t pts; /**< time stamp to show frame
> - (in timebase units) */
> - unsigned long duration; /**< duration to show frame
> - (in timebase units) */
> - uint32_t flags; /**< flags for this frame */
> - uint64_t sse[4];
> - int have_sse; /**< true if we have pending sse[] */
> - uint64_t frame_number;
> - struct FrameListData *next;
> -};
> -
> typedef struct AOMEncoderContext {
> AVClass *class;
> AVBSFContext *bsf;
> @@ -71,7 +54,8 @@ typedef struct AOMEncoderContext {
> struct aom_image rawimg;
> struct aom_fixed_buf twopass_stats;
> unsigned twopass_stats_size;
> - struct FrameListData *coded_frame_list;
> + PacketList coded_frame_list;
> + AVPacket *pkt;
Renaming this variable to avpkt would improve clarity by simplifying
distinguishing it from the aom_codec_cx_pkt packets.
> int cpu_used;
> int auto_alt_ref;
> int arnr_max_frames;
> @@ -283,33 +267,6 @@ static av_cold void dump_enc_cfg(AVCodecContext *avctx,
> av_log(avctx, level, "\n");
> }
>
> -static void coded_frame_add(void *list, struct FrameListData *cx_frame)
> -{
> - struct FrameListData **p = list;
> -
> - while (*p)
> - p = &(*p)->next;
> - *p = cx_frame;
> - cx_frame->next = NULL;
> -}
> -
> -static av_cold void free_coded_frame(struct FrameListData *cx_frame)
> -{
> - av_freep(&cx_frame->buf);
> - av_freep(&cx_frame);
> -}
> -
> -static av_cold void free_frame_list(struct FrameListData *list)
> -{
> - struct FrameListData *p = list;
> -
> - while (p) {
> - list = list->next;
> - free_coded_frame(p);
> - p = list;
> - }
> -}
> -
> static av_cold int codecctl_int(AVCodecContext *avctx,
> #ifdef UENUM1BYTE
> aome_enc_control_id id,
> @@ -432,7 +389,8 @@ static av_cold int aom_free(AVCodecContext *avctx)
> aom_codec_destroy(&ctx->encoder);
> av_freep(&ctx->twopass_stats.buf);
> av_freep(&avctx->stats_out);
> - free_frame_list(ctx->coded_frame_list);
> + avpriv_packet_list_free(&ctx->coded_frame_list);
> + av_packet_free(&ctx->pkt);
> av_bsf_free(&ctx->bsf);
> return 0;
> }
> @@ -1042,6 +1000,10 @@ static av_cold int aom_init(AVCodecContext *avctx,
> return ret;
> }
>
> + ctx->pkt = av_packet_alloc();
> + if (!ctx->pkt)
> + return AVERROR(ENOMEM);
> +
This encoder does not have the INIT_CLEANUP flag set, so everything
leaks in case the above allocation fails. In fact, it seems like there
are already leaks in several errors paths in this function.
> if (enccfg.rc_end_usage == AOM_CBR ||
> enccfg.g_pass != AOM_RC_ONE_PASS) {
> cpb_props->max_bitrate = avctx->rc_max_rate;
> @@ -1053,25 +1015,40 @@ static av_cold int aom_init(AVCodecContext *avctx,
> return 0;
> }
>
> -static inline void cx_pktcpy(AOMContext *ctx,
> - struct FrameListData *dst,
> +static inline int cx_pktcpy(AVCodecContext *avctx,
We should not override the compiler's inlining behaviour unless we have
a good reason to do so, so you could remove it while at it.
> + AVPacket *dst,
Wrong indentation.
> const struct aom_codec_cx_pkt *src)
> {
> - dst->pts = src->data.frame.pts;
> - dst->duration = src->data.frame.duration;
> - dst->flags = src->data.frame.flags;
> - dst->sz = src->data.frame.sz;
> - dst->buf = src->data.frame.buf;
> + AOMContext *ctx = avctx->priv_data;
> + int av_unused pict_type;
> + int ret;
> +
> + av_packet_unref(dst);
Can dst ever be non-blank here (i.e. before the unref)?
> + ret = ff_get_encode_buffer(avctx, dst, src->data.frame.sz, 0);
> + if (ret < 0) {
> + av_log(avctx, AV_LOG_ERROR,
> + "Error getting output packet of size %"SIZE_SPECIFIER".\n", src->data.frame.sz);
> + return ret;
> + }
> + memcpy(dst->data, src->data.frame.buf, src->data.frame.sz);
> + dst->pts = dst->dts = src->data.frame.pts;
> +
> + if (src->data.frame.flags & AOM_FRAME_IS_KEY) {
> + dst->flags |= AV_PKT_FLAG_KEY;
> #ifdef AOM_FRAME_IS_INTRAONLY
> - dst->frame_number = ++ctx->frame_number;
> - dst->have_sse = ctx->have_sse;
> + pict_type = AV_PICTURE_TYPE_I;
> + } else if (src->data.frame.flags & AOM_FRAME_IS_INTRAONLY) {
> + pict_type = AV_PICTURE_TYPE_I;
> + } else {
> + pict_type = AV_PICTURE_TYPE_P;
> + }
> +
> if (ctx->have_sse) {
> - /* associate last-seen SSE to the frame. */
> - /* Transfers ownership from ctx to dst. */
> - memcpy(dst->sse, ctx->sse, sizeof(dst->sse));
> + ff_side_data_set_encoder_stats(dst, 0, ctx->sse + 1, 3, pict_type);
This function can fail.
> ctx->have_sse = 0;
> - }
> #endif
> + }
> + return 0;
> }
>
> /**
> @@ -1081,50 +1058,32 @@ static inline void cx_pktcpy(AOMContext *ctx,
> * @return packet data size on success
> * @return a negative AVERROR on error
> */
> -static int storeframe(AVCodecContext *avctx, struct FrameListData *cx_frame,
> - AVPacket *pkt)
> +static int storeframe(AVCodecContext *avctx, AVPacket *dst, AVPacket *src)
> {
> AOMContext *ctx = avctx->priv_data;
> - int av_unused pict_type;
> - int ret = ff_get_encode_buffer(avctx, pkt, cx_frame->sz, 0);
> - if (ret < 0) {
> - av_log(avctx, AV_LOG_ERROR,
> - "Error getting output packet of size %"SIZE_SPECIFIER".\n", cx_frame->sz);
> - return ret;
> - }
> - memcpy(pkt->data, cx_frame->buf, pkt->size);
> - pkt->pts = pkt->dts = cx_frame->pts;
> + const uint8_t *sd;
> + size_t size;
> + int ret;
>
> - if (!!(cx_frame->flags & AOM_FRAME_IS_KEY)) {
> - pkt->flags |= AV_PKT_FLAG_KEY;
> -#ifdef AOM_FRAME_IS_INTRAONLY
> - pict_type = AV_PICTURE_TYPE_I;
> - } else if (cx_frame->flags & AOM_FRAME_IS_INTRAONLY) {
> - pict_type = AV_PICTURE_TYPE_I;
> - } else {
> - pict_type = AV_PICTURE_TYPE_P;
> - }
> -
> - ff_side_data_set_encoder_stats(pkt, 0, cx_frame->sse + 1,
> - cx_frame->have_sse ? 3 : 0, pict_type);
> + av_packet_move_ref(dst, src);
>
> - if (cx_frame->have_sse) {
> + sd = av_packet_get_side_data(dst, AV_PKT_DATA_QUALITY_STATS, &size);
> + if (sd && size >= 4 + 4 + 8 * 3) {
> int i;
> + sd += 4 + 4;
> for (i = 0; i < 3; ++i) {
> - avctx->error[i] += cx_frame->sse[i + 1];
> + avctx->error[i] += bytestream_get_le64(&sd);
> }
> - cx_frame->have_sse = 0;
> -#endif
> }
>
> if (avctx->flags & AV_CODEC_FLAG_GLOBAL_HEADER) {
> - ret = av_bsf_send_packet(ctx->bsf, pkt);
> + ret = av_bsf_send_packet(ctx->bsf, dst);
> if (ret < 0) {
> av_log(avctx, AV_LOG_ERROR, "extract_extradata filter "
> "failed to send input packet\n");
> return ret;
> }
> - ret = av_bsf_receive_packet(ctx->bsf, pkt);
> + ret = av_bsf_receive_packet(ctx->bsf, dst);
>
> if (ret < 0) {
> av_log(avctx, AV_LOG_ERROR, "extract_extradata filter "
> @@ -1132,7 +1091,7 @@ static int storeframe(AVCodecContext *avctx, struct FrameListData *cx_frame,
> return ret;
> }
> }
> - return pkt->size;
> + return dst->size;
> }
>
> /**
> @@ -1148,16 +1107,14 @@ static int queue_frames(AVCodecContext *avctx, AVPacket *pkt_out)
> AOMContext *ctx = avctx->priv_data;
> const struct aom_codec_cx_pkt *pkt;
> const void *iter = NULL;
> - int size = 0;
> + int ret, size = 0;
>
> - if (ctx->coded_frame_list) {
> - struct FrameListData *cx_frame = ctx->coded_frame_list;
> + if (!avpriv_packet_list_get(&ctx->coded_frame_list, ctx->pkt)) {
> /* return the leading frame if we've already begun queueing */
> - size = storeframe(avctx, cx_frame, pkt_out);
> - if (size < 0)
> - return size;
> - ctx->coded_frame_list = cx_frame->next;
> - free_coded_frame(cx_frame);
> + ret = storeframe(avctx, pkt_out, ctx->pkt);
> + if (ret < 0)
> + goto fail;
> + size = ret;
> }
>
> /* consume all available output from the encoder before returning. buffers
> @@ -1165,37 +1122,21 @@ static int queue_frames(AVCodecContext *avctx, AVPacket *pkt_out)
> while ((pkt = aom_codec_get_cx_data(&ctx->encoder, &iter))) {
> switch (pkt->kind) {
> case AOM_CODEC_CX_FRAME_PKT:
> + ret = cx_pktcpy(avctx, ctx->pkt, pkt);
> + if (ret < 0)
> + goto fail;
> if (!size) {
> - struct FrameListData cx_frame;
> -
> /* avoid storing the frame when the list is empty and we haven't yet
> * provided a frame for output */
> - av_assert0(!ctx->coded_frame_list);
> - cx_pktcpy(ctx, &cx_frame, pkt);
> - size = storeframe(avctx, &cx_frame, pkt_out);
> - if (size < 0)
> - return size;
> + av_assert0(!ctx->coded_frame_list.head);
> + ret = storeframe(avctx, pkt_out, ctx->pkt);
> + if (ret < 0)
> + goto fail;
> + size = ret;
> } else {
> - struct FrameListData *cx_frame =
> - av_malloc(sizeof(struct FrameListData));
> -
> - if (!cx_frame) {
> - av_log(avctx, AV_LOG_ERROR,
> - "Frame queue element alloc failed\n");
> - return AVERROR(ENOMEM);
> - }
> - cx_pktcpy(ctx, cx_frame, pkt);
> - cx_frame->buf = av_malloc(cx_frame->sz);
> -
> - if (!cx_frame->buf) {
> - av_log(avctx, AV_LOG_ERROR,
> - "Data buffer alloc (%"SIZE_SPECIFIER" bytes) failed\n",
> - cx_frame->sz);
> - av_freep(&cx_frame);
> - return AVERROR(ENOMEM);
> - }
> - memcpy(cx_frame->buf, pkt->data.frame.buf, pkt->data.frame.sz);
I am shocked to see that there were two memcpies.
> - coded_frame_add(&ctx->coded_frame_list, cx_frame);
> + ret = avpriv_packet_list_put(&ctx->coded_frame_list, ctx->pkt, NULL, 0);
> + if (ret < 0)
> + goto fail;
wtf: Any error that queue_frames() returns will be translated to
"got_packet = 1" by the caller (with return code 0). Error handling in
this encoder seems to be a joke.
> }
> break;
> case AOM_CODEC_STATS_PKT:
> @@ -1236,6 +1177,10 @@ static int queue_frames(AVCodecContext *avctx, AVPacket *pkt_out)
> }
>
> return size;
> +fail:
> + av_packet_unref(ctx->pkt);
> + av_packet_unref(pkt_out);
> + return ret;
> }
>
> static enum AVPixelFormat aomfmt_to_pixfmt(struct aom_image *img)
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