[SCM] libav/experimental: Add support for two pass encoding in libtheora
siretart at users.alioth.debian.org
siretart at users.alioth.debian.org
Sun Jun 30 16:54:45 UTC 2013
The following commit has been merged in the experimental branch:
commit b0a6d9ca8629c934c43634a1538787c08f48ecc0
Author: David Conrad <lessen42 at gmail.com>
Date: Sun Nov 22 21:08:40 2009 +0000
Add support for two pass encoding in libtheora
Originally committed as revision 20581 to svn://svn.ffmpeg.org/ffmpeg/trunk
diff --git a/libavcodec/libtheoraenc.c b/libavcodec/libtheoraenc.c
index 7d62508..4ff30d6 100644
--- a/libavcodec/libtheoraenc.c
+++ b/libavcodec/libtheoraenc.c
@@ -33,6 +33,7 @@
/* FFmpeg includes */
#include "libavutil/intreadwrite.h"
#include "libavutil/log.h"
+#include "libavutil/base64.h"
#include "avcodec.h"
/* libtheora includes */
@@ -40,6 +41,9 @@
typedef struct TheoraContext {
th_enc_ctx *t_state;
+ uint8_t *stats;
+ int stats_size;
+ int stats_offset;
} TheoraContext;
/*!
@@ -78,6 +82,62 @@ static int concatenate_packet(unsigned int* offset,
return 0;
}
+static int get_stats(AVCodecContext *avctx, int eos)
+{
+ TheoraContext *h = avctx->priv_data;
+ uint8_t *buf;
+ int bytes;
+
+ bytes = th_encode_ctl(h->t_state, TH_ENCCTL_2PASS_OUT, &buf, sizeof(buf));
+ if (bytes < 0) {
+ av_log(avctx, AV_LOG_ERROR, "Error getting first pass stats\n");
+ return -1;
+ }
+ if (!eos) {
+ h->stats = av_fast_realloc(h->stats, &h->stats_size,
+ h->stats_offset + bytes);
+ memcpy(h->stats + h->stats_offset, buf, bytes);
+ h->stats_offset += bytes;
+ } else {
+ int b64_size = ((h->stats_offset + 2) / 3) * 4 + 1;
+ // libtheora generates a summary header at the end
+ memcpy(h->stats, buf, bytes);
+ avctx->stats_out = av_malloc(b64_size);
+ av_base64_encode(avctx->stats_out, b64_size, h->stats, h->stats_offset);
+ }
+ return 0;
+}
+
+// libtheora won't read the entire buffer we give it at once, so we have to
+// repeatedly submit it...
+static int submit_stats(AVCodecContext *avctx)
+{
+ TheoraContext *h = avctx->priv_data;
+ int bytes;
+ if (!h->stats) {
+ if (!avctx->stats_in) {
+ av_log(avctx, AV_LOG_ERROR, "No statsfile for second pass\n");
+ return -1;
+ }
+ h->stats_size = strlen(avctx->stats_in) * 3/4;
+ h->stats = av_malloc(h->stats_size);
+ h->stats_size = av_base64_decode(h->stats, avctx->stats_in, h->stats_size);
+ }
+ while (h->stats_size - h->stats_offset > 0) {
+ bytes = th_encode_ctl(h->t_state, TH_ENCCTL_2PASS_IN,
+ h->stats + h->stats_offset,
+ h->stats_size - h->stats_offset);
+ if (bytes < 0) {
+ av_log(avctx, AV_LOG_ERROR, "Error submitting stats\n");
+ return -1;
+ }
+ if (!bytes)
+ return 0;
+ h->stats_offset += bytes;
+ }
+ return 0;
+}
+
static av_cold int encode_init(AVCodecContext* avc_context)
{
th_info t_info;
@@ -138,6 +198,15 @@ static av_cold int encode_init(AVCodecContext* avc_context)
return -1;
}
+ // need to enable 2 pass (via TH_ENCCTL_2PASS_) before encoding headers
+ if (avc_context->flags & CODEC_FLAG_PASS1) {
+ if (get_stats(avc_context, 0))
+ return -1;
+ } else if (avc_context->flags & CODEC_FLAG_PASS2) {
+ if (submit_stats(avc_context))
+ return -1;
+ }
+
/*
Output first header packet consisting of theora
header, comment, and tables.
@@ -173,6 +242,15 @@ static int encode_frame(AVCodecContext* avc_context, uint8_t *outbuf,
assert(avc_context->pix_fmt == PIX_FMT_YUV420P);
+ // EOS, finish and get 1st pass stats if applicable
+ if (!frame) {
+ th_encode_packetout(h->t_state, 1, &o_packet);
+ if (avc_context->flags & CODEC_FLAG_PASS1)
+ if (get_stats(avc_context, 1))
+ return -1;
+ return 0;
+ }
+
/* Copy planes to the theora yuv_buffer */
for (i = 0; i < 3; i++) {
t_yuv_buffer[i].width = FFALIGN(avc_context->width, 16) >> !!i;
@@ -181,6 +259,10 @@ static int encode_frame(AVCodecContext* avc_context, uint8_t *outbuf,
t_yuv_buffer[i].data = frame->data[i];
}
+ if (avc_context->flags & CODEC_FLAG_PASS2)
+ if (submit_stats(avc_context))
+ return -1;
+
/* Now call into theora_encode_YUVin */
result = th_encode_ycbcr_in(h->t_state, t_yuv_buffer);
if (result) {
@@ -200,6 +282,10 @@ static int encode_frame(AVCodecContext* avc_context, uint8_t *outbuf,
return -1;
}
+ if (avc_context->flags & CODEC_FLAG_PASS1)
+ if (get_stats(avc_context, 0))
+ return -1;
+
/* Pick up returned ogg_packet */
result = th_encode_packetout(h->t_state, 0, &o_packet);
switch (result) {
@@ -229,31 +315,16 @@ static int encode_frame(AVCodecContext* avc_context, uint8_t *outbuf,
static av_cold int encode_close(AVCodecContext* avc_context)
{
- ogg_packet o_packet;
TheoraContext *h = avc_context->priv_data;
- int result;
- const char* message;
- result = th_encode_packetout(h->t_state, 1, &o_packet);
th_encode_free(h->t_state);
+ av_freep(&h->stats);
av_freep(&avc_context->coded_frame);
+ av_freep(&avc_context->stats_out);
av_freep(&avc_context->extradata);
avc_context->extradata_size = 0;
- switch (result) {
- case 0: /* No packet is ready */
- case -1: /* Encoding finished */
- return 0;
- case 1:
- /* We have a packet */
- message = "gave us a packet";
- break;
- default:
- message = "unknown reason";
- break;
- }
- av_log(avc_context, AV_LOG_ERROR, "theora_encode_packetout failed (%s) [%d]\n", message, result);
- return -1;
+ return 0;
}
static const enum PixelFormat supported_pixel_formats[] = { PIX_FMT_YUV420P, PIX_FMT_NONE };
@@ -267,6 +338,7 @@ AVCodec libtheora_encoder = {
.init = encode_init,
.close = encode_close,
.encode = encode_frame,
+ .capabilities = CODEC_CAP_DELAY, // needed to get the statsfile summary
.pix_fmts = supported_pixel_formats,
.long_name = NULL_IF_CONFIG_SMALL("libtheora Theora"),
};
--
Libav/FFmpeg packaging
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