[FFmpeg-devel] [PATCH v3] avcodec/libx264: fix extradata when config annexb=0

[Zhao Zhili]

From: Zhao Zhili <zhilizhao at tencent.com>

---
v3: Remove unnecessary inclusion

 configure            |   2 +-
 libavcodec/libx264.c | 132 +++++++++++++++++++++++++++++++++++--------
 2 files changed, 109 insertions(+), 25 deletions(-)

diff --git a/configure b/configure
index db7dc89755..24cb897d28 100755
--- a/configure
+++ b/configure
@@ -3491,7 +3491,7 @@ libwebp_encoder_deps="libwebp"
 libwebp_anim_encoder_deps="libwebp"
 libx262_encoder_deps="libx262"
 libx264_encoder_deps="libx264"
-libx264_encoder_select="atsc_a53"
+libx264_encoder_select="atsc_a53 h264parse"
 libx264rgb_encoder_deps="libx264"
 libx264rgb_encoder_select="libx264_encoder"
 libx265_encoder_deps="libx265"
diff --git a/libavcodec/libx264.c b/libavcodec/libx264.c
index 10d646bd76..b90e3f4fe1 100644
--- a/libavcodec/libx264.c
+++ b/libavcodec/libx264.c
@@ -34,6 +34,7 @@
 #include "avcodec.h"
 #include "codec_internal.h"
 #include "encode.h"
+#include "h264_ps.h"
 #include "internal.h"
 #include "packet_internal.h"
 #include "atsc_a53.h"
@@ -865,6 +866,110 @@ static int convert_pix_fmt(enum AVPixelFormat pix_fmt)
     return 0;
 }
 
+static int set_avcc_extradata(AVCodecContext *avctx, x264_nal_t *nal, int nnal)
+{
+    X264Context *x4 = avctx->priv_data;
+    x264_nal_t *sps_nal = NULL;
+    x264_nal_t *pps_nal = NULL;
+    uint8_t *p, *sps;
+    int ret;
+
+    /* We know it's in the order of SPS/PPS/SEI, but it's not documented in x264 API.
+     * The x264 param i_sps_id implies there is a single pair of SPS/PPS.
+     */
+    for (int i = 0; i < nnal; i++) {
+        if (nal[i].i_type == NAL_SPS)
+            sps_nal = &nal[i];
+        else if (nal[i].i_type == NAL_PPS)
+            pps_nal = &nal[i];
+    }
+    if (!sps_nal || !pps_nal)
+        return AVERROR_EXTERNAL;
+
+    avctx->extradata_size = sps_nal->i_payload + pps_nal->i_payload + 7;
+    avctx->extradata = av_mallocz(avctx->extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
+    if (!avctx->extradata)
+        return AVERROR(ENOMEM);
+
+    // Now create AVCDecoderConfigurationRecord
+    p = avctx->extradata;
+    // Skip size part
+    sps = sps_nal->p_payload + 4;
+    *p++ = 1; // version
+    *p++ = sps[1]; // AVCProfileIndication
+    *p++ = sps[2]; // profile_compatibility
+    *p++ = sps[3]; // AVCLevelIndication
+    *p++ = 0xFF;
+    *p++ = 0xE0 | 0x01; // 3 bits reserved (111) + 5 bits number of sps
+    memcpy(p, sps_nal->p_payload + 2, sps_nal->i_payload - 2);
+    // Make sps has AV_INPUT_BUFFER_PADDING_SIZE padding, so it can be used
+    // with GetBitContext
+    sps = p + 2;
+    p += sps_nal->i_payload - 2;
+    *p++ = 1;
+    memcpy(p, pps_nal->p_payload + 2, pps_nal->i_payload - 2);
+    p += pps_nal->i_payload - 2;
+
+    if (sps[3] != 66 && sps[3] != 77 && sps[3] != 88) {
+        GetBitContext gbc;
+        H264ParamSets ps = { 0 };
+
+        init_get_bits8(&gbc, sps, sps_nal->i_payload - 4);
+        skip_bits(&gbc, 8);
+        ret = ff_h264_decode_seq_parameter_set(&gbc, avctx, &ps, 1);
+        if (ret < 0)
+            return ret;
+
+        ps.sps = ps.sps_list[x4->params.i_sps_id];
+        *p++ = 0xFC | ps.sps->chroma_format_idc;
+        *p++ = 0xF8 | (ps.sps->bit_depth_luma - 8);
+        *p++ = 0xF8 | (ps.sps->bit_depth_chroma - 8);
+        *p++ = 0;
+        ff_h264_ps_uninit(&ps);
+    }
+    av_assert0(avctx->extradata + avctx->extradata_size >= p);
+    avctx->extradata_size = p - avctx->extradata;
+
+    return 0;
+}
+
+static int set_extradata(AVCodecContext *avctx)
+{
+    X264Context *x4 = avctx->priv_data;
+    x264_nal_t *nal;
+    uint8_t *p;
+    int nnal, s;
+
+    s = x264_encoder_headers(x4->enc, &nal, &nnal);
+    if (s < 0)
+        return AVERROR_EXTERNAL;
+
+    if (!x4->params.b_annexb)
+        return set_avcc_extradata(avctx, nal, nnal);
+
+    avctx->extradata = p = av_mallocz(s + AV_INPUT_BUFFER_PADDING_SIZE);
+    if (!p)
+        return AVERROR(ENOMEM);
+
+    for (int i = 0; i < nnal; i++) {
+        /* Don't put the SEI in extradata. */
+        if (nal[i].i_type == NAL_SEI) {
+            av_log(avctx, AV_LOG_INFO, "%s\n", nal[i].p_payload + 25);
+            x4->sei_size = nal[i].i_payload;
+            x4->sei = av_malloc(x4->sei_size);
+            if (!x4->sei)
+                return AVERROR(ENOMEM);
+            memcpy(x4->sei, nal[i].p_payload, nal[i].i_payload);
+            continue;
+        }
+        memcpy(p, nal[i].p_payload, nal[i].i_payload);
+        p += nal[i].i_payload;
+    }
+    avctx->extradata_size = p - avctx->extradata;
+
+    return 0;
+}
+
 #define PARSE_X264_OPT(name, var)\
     if (x4->var && x264_param_parse(&x4->params, name, x4->var) < 0) {\
         av_log(avctx, AV_LOG_ERROR, "Error parsing option '%s' with value '%s'.\n", name, x4->var);\
@@ -1233,30 +1338,9 @@ FF_ENABLE_DEPRECATION_WARNINGS
         return AVERROR_EXTERNAL;
 
     if (avctx->flags & AV_CODEC_FLAG_GLOBAL_HEADER) {
-        x264_nal_t *nal;
-        uint8_t *p;
-        int nnal, s, i;
-
-        s = x264_encoder_headers(x4->enc, &nal, &nnal);
-        avctx->extradata = p = av_mallocz(s + AV_INPUT_BUFFER_PADDING_SIZE);
-        if (!p)
-            return AVERROR(ENOMEM);
-
-        for (i = 0; i < nnal; i++) {
-            /* Don't put the SEI in extradata. */
-            if (nal[i].i_type == NAL_SEI) {
-                av_log(avctx, AV_LOG_INFO, "%s\n", nal[i].p_payload+25);
-                x4->sei_size = nal[i].i_payload;
-                x4->sei      = av_malloc(x4->sei_size);
-                if (!x4->sei)
-                    return AVERROR(ENOMEM);
-                memcpy(x4->sei, nal[i].p_payload, nal[i].i_payload);
-                continue;
-            }
-            memcpy(p, nal[i].p_payload, nal[i].i_payload);
-            p += nal[i].i_payload;
-        }
-        avctx->extradata_size = p - avctx->extradata;
+        ret = set_extradata(avctx);
+        if (ret < 0)
+            return ret;
     }
 
     cpb_props = ff_encode_add_cpb_side_data(avctx);
-- 
2.25.1