ratecontrol: Reorder functions to avoid forward declarations

libavcodec/ratecontrol.c

@@ -42,24 +42,406 @@
 #define M_E 2.718281828
 #endif
 
-static int init_pass2(MpegEncContext *s);
+static inline double qp2bits(RateControlEntry *rce, double qp)
+{
+    if (qp <= 0.0) {
+        av_log(NULL, AV_LOG_ERROR, "qp<=0.0\n");
+    }
+    return rce->qscale * (double)(rce->i_tex_bits + rce->p_tex_bits + 1) / qp;
+}
+
+static inline double bits2qp(RateControlEntry *rce, double bits)
+{
+    if (bits < 0.9) {
+        av_log(NULL, AV_LOG_ERROR, "bits<0.9\n");
+    }
+    return rce->qscale * (double)(rce->i_tex_bits + rce->p_tex_bits + 1) / bits;
+}
+
+static double get_diff_limited_q(MpegEncContext *s, RateControlEntry *rce, double q)
+{
+    RateControlContext *rcc   = &s->rc_context;
+    AVCodecContext *a         = s->avctx;
+    const int pict_type       = rce->new_pict_type;
+    const double last_p_q     = rcc->last_qscale_for[AV_PICTURE_TYPE_P];
+    const double last_non_b_q = rcc->last_qscale_for[rcc->last_non_b_pict_type];
+
+    if (pict_type == AV_PICTURE_TYPE_I &&
+        (a->i_quant_factor > 0.0 || rcc->last_non_b_pict_type == AV_PICTURE_TYPE_P))
+        q = last_p_q * FFABS(a->i_quant_factor) + a->i_quant_offset;
+    else if (pict_type == AV_PICTURE_TYPE_B &&
+             a->b_quant_factor > 0.0)
+        q = last_non_b_q * a->b_quant_factor + a->b_quant_offset;
+    if (q < 1)
+        q = 1;
+
+    /* last qscale / qdiff stuff */
+    if (rcc->last_non_b_pict_type == pict_type || pict_type != AV_PICTURE_TYPE_I) {
+        double last_q     = rcc->last_qscale_for[pict_type];
+        const int maxdiff = FF_QP2LAMBDA * a->max_qdiff;
+
+        if (q > last_q + maxdiff)
+            q = last_q + maxdiff;
+        else if (q < last_q - maxdiff)
+            q = last_q - maxdiff;
+    }
+
+    rcc->last_qscale_for[pict_type] = q; // Note we cannot do that after blurring
+
+    if (pict_type != AV_PICTURE_TYPE_B)
+        rcc->last_non_b_pict_type = pict_type;
+
+    return q;
+}
+
+/**
+ * Get the qmin & qmax for pict_type.
+ */
+static void get_qminmax(int *qmin_ret, int *qmax_ret, MpegEncContext *s, int pict_type)
+{
+    int qmin = s->lmin;
+    int qmax = s->lmax;
+
+    assert(qmin <= qmax);
+
+    switch (pict_type) {
+    case AV_PICTURE_TYPE_B:
+        qmin = (int)(qmin * FFABS(s->avctx->b_quant_factor) + s->avctx->b_quant_offset + 0.5);
+        qmax = (int)(qmax * FFABS(s->avctx->b_quant_factor) + s->avctx->b_quant_offset + 0.5);
+        break;
+    case AV_PICTURE_TYPE_I:
+        qmin = (int)(qmin * FFABS(s->avctx->i_quant_factor) + s->avctx->i_quant_offset + 0.5);
+        qmax = (int)(qmax * FFABS(s->avctx->i_quant_factor) + s->avctx->i_quant_offset + 0.5);
+        break;
+    }
+
+    qmin = av_clip(qmin, 1, FF_LAMBDA_MAX);
+    qmax = av_clip(qmax, 1, FF_LAMBDA_MAX);
+
+    if (qmax < qmin)
+        qmax = qmin;
+
+    *qmin_ret = qmin;
+    *qmax_ret = qmax;
+}
+
+static double modify_qscale(MpegEncContext *s, RateControlEntry *rce,
+                            double q, int frame_num)
+{
+    RateControlContext *rcc  = &s->rc_context;
+    const double buffer_size = s->avctx->rc_buffer_size;
+    const double fps         = 1 / av_q2d(s->avctx->time_base);
+    const double min_rate    = s->avctx->rc_min_rate / fps;
+    const double max_rate    = s->avctx->rc_max_rate / fps;
+    const int pict_type      = rce->new_pict_type;
+    int qmin, qmax;
+
+    get_qminmax(&qmin, &qmax, s, pict_type);
+
+    /* modulation */
+    if (s->rc_qmod_freq &&
+        frame_num % s->rc_qmod_freq == 0 &&
+        pict_type == AV_PICTURE_TYPE_P)
+        q *= s->rc_qmod_amp;
+
+    /* buffer overflow/underflow protection */
+    if (buffer_size) {
+        double expected_size = rcc->buffer_index;
+        double q_limit;
+
+        if (min_rate) {
+            double d = 2 * (buffer_size - expected_size) / buffer_size;
+            if (d > 1.0)
+                d = 1.0;
+            else if (d < 0.0001)
+                d = 0.0001;
+            q *= pow(d, 1.0 / s->rc_buffer_aggressivity);
+
+            q_limit = bits2qp(rce,
+                              FFMAX((min_rate - buffer_size + rcc->buffer_index) *
+                                    s->avctx->rc_min_vbv_overflow_use, 1));
+
+            if (q > q_limit) {
+                if (s->avctx->debug & FF_DEBUG_RC)
+                    av_log(s->avctx, AV_LOG_DEBUG,
+                           "limiting QP %f -> %f\n", q, q_limit);
+                q = q_limit;
+            }
+        }
+
+        if (max_rate) {
+            double d = 2 * expected_size / buffer_size;
+            if (d > 1.0)
+                d = 1.0;
+            else if (d < 0.0001)
+                d = 0.0001;
+            q /= pow(d, 1.0 / s->rc_buffer_aggressivity);
+
+            q_limit = bits2qp(rce,
+                              FFMAX(rcc->buffer_index *
+                                    s->avctx->rc_max_available_vbv_use,
+                                    1));
+            if (q < q_limit) {
+                if (s->avctx->debug & FF_DEBUG_RC)
+                    av_log(s->avctx, AV_LOG_DEBUG,
+                           "limiting QP %f -> %f\n", q, q_limit);
+                q = q_limit;
+            }
+        }
+    }
+    ff_dlog(s, "q:%f max:%f min:%f size:%f index:%f agr:%f\n",
+            q, max_rate, min_rate, buffer_size, rcc->buffer_index,
+            s->rc_buffer_aggressivity);
+    if (s->rc_qsquish == 0.0 || qmin == qmax) {
+        if (q < qmin)
+            q = qmin;
+        else if (q > qmax)
+            q = qmax;
+    } else {
+        double min2 = log(qmin);
+        double max2 = log(qmax);
+
+        q  = log(q);
+        q  = (q - min2) / (max2 - min2) - 0.5;
+        q *= -4.0;
+        q  = 1.0 / (1.0 + exp(q));
+        q  = q * (max2 - min2) + min2;
+
+        q = exp(q);
+    }
+
+    return q;
+}
+
+/**
+ * Modify the bitrate curve from pass1 for one frame.
+ */
 static double get_qscale(MpegEncContext *s, RateControlEntry *rce,
-                         double rate_factor, int frame_num);
+                         double rate_factor, int frame_num)
+{
+    RateControlContext *rcc = &s->rc_context;
+    AVCodecContext *a       = s->avctx;
+    const int pict_type     = rce->new_pict_type;
+    const double mb_num     = s->mb_num;
+    double q, bits;
+    int i;
+
+    double const_values[] = {
+        M_PI,
+        M_E,
+        rce->i_tex_bits * rce->qscale,
+        rce->p_tex_bits * rce->qscale,
+        (rce->i_tex_bits + rce->p_tex_bits) * (double)rce->qscale,
+        rce->mv_bits / mb_num,
+        rce->pict_type == AV_PICTURE_TYPE_B ? (rce->f_code + rce->b_code) * 0.5 : rce->f_code,
+        rce->i_count / mb_num,
+        rce->mc_mb_var_sum / mb_num,
+        rce->mb_var_sum / mb_num,
+        rce->pict_type == AV_PICTURE_TYPE_I,
+        rce->pict_type == AV_PICTURE_TYPE_P,
+        rce->pict_type == AV_PICTURE_TYPE_B,
+        rcc->qscale_sum[pict_type] / (double)rcc->frame_count[pict_type],
+        a->qcompress,
+        rcc->i_cplx_sum[AV_PICTURE_TYPE_I] / (double)rcc->frame_count[AV_PICTURE_TYPE_I],
+        rcc->i_cplx_sum[AV_PICTURE_TYPE_P] / (double)rcc->frame_count[AV_PICTURE_TYPE_P],
+        rcc->p_cplx_sum[AV_PICTURE_TYPE_P] / (double)rcc->frame_count[AV_PICTURE_TYPE_P],
+        rcc->p_cplx_sum[AV_PICTURE_TYPE_B] / (double)rcc->frame_count[AV_PICTURE_TYPE_B],
+        (rcc->i_cplx_sum[pict_type] + rcc->p_cplx_sum[pict_type]) / (double)rcc->frame_count[pict_type],
+        0
+    };
+
+    bits = av_expr_eval(rcc->rc_eq_eval, const_values, rce);
+    if (isnan(bits)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Error evaluating rc_eq \"%s\"\n", s->rc_eq);
+        return -1;
+    }
+
+    rcc->pass1_rc_eq_output_sum += bits;
+    bits *= rate_factor;
+    if (bits < 0.0)
+        bits = 0.0;
+    bits += 1.0; // avoid 1/0 issues
+
+    /* user override */
+    for (i = 0; i < s->avctx->rc_override_count; i++) {
+        RcOverride *rco = s->avctx->rc_override;
+        if (rco[i].start_frame > frame_num)
+            continue;
+        if (rco[i].end_frame < frame_num)
+            continue;
+
+        if (rco[i].qscale)
+            bits = qp2bits(rce, rco[i].qscale);  // FIXME move at end to really force it?
+        else
+            bits *= rco[i].quality_factor;
+    }
+
+    q = bits2qp(rce, bits);
+
+    /* I/B difference */
+    if (pict_type == AV_PICTURE_TYPE_I && s->avctx->i_quant_factor < 0.0)
+        q = -q * s->avctx->i_quant_factor + s->avctx->i_quant_offset;
+    else if (pict_type == AV_PICTURE_TYPE_B && s->avctx->b_quant_factor < 0.0)
+        q = -q * s->avctx->b_quant_factor + s->avctx->b_quant_offset;
+    if (q < 1)
+        q = 1;
+
+    return q;
+}
+
+static int init_pass2(MpegEncContext *s)
+{
+    RateControlContext *rcc = &s->rc_context;
+    AVCodecContext *a       = s->avctx;
+    int i, toobig;
+    double fps             = 1 / av_q2d(s->avctx->time_base);
+    double complexity[5]   = { 0 }; // approximate bits at quant=1
+    uint64_t const_bits[5] = { 0 }; // quantizer independent bits
+    uint64_t all_const_bits;
+    uint64_t all_available_bits = (uint64_t)(s->bit_rate *
+                                             (double)rcc->num_entries / fps);
+    double rate_factor          = 0;
+    double step;
+    const int filter_size = (int)(a->qblur * 4) | 1;
+    double expected_bits;
+    double *qscale, *blurred_qscale, qscale_sum;
+
+    /* find complexity & const_bits & decide the pict_types */
+    for (i = 0; i < rcc->num_entries; i++) {
+        RateControlEntry *rce = &rcc->entry[i];
+
+        rce->new_pict_type                = rce->pict_type;
+        rcc->i_cplx_sum[rce->pict_type]  += rce->i_tex_bits * rce->qscale;
+        rcc->p_cplx_sum[rce->pict_type]  += rce->p_tex_bits * rce->qscale;
+        rcc->mv_bits_sum[rce->pict_type] += rce->mv_bits;
+        rcc->frame_count[rce->pict_type]++;
+
+        complexity[rce->new_pict_type] += (rce->i_tex_bits + rce->p_tex_bits) *
+                                          (double)rce->qscale;
+        const_bits[rce->new_pict_type] += rce->mv_bits + rce->misc_bits;
+    }
+
+    all_const_bits = const_bits[AV_PICTURE_TYPE_I] +
+                     const_bits[AV_PICTURE_TYPE_P] +
+                     const_bits[AV_PICTURE_TYPE_B];
+
+    if (all_available_bits < all_const_bits) {
+        av_log(s->avctx, AV_LOG_ERROR, "requested bitrate is too low\n");
+        return -1;
+    }
+
+    qscale         = av_malloc(sizeof(double) * rcc->num_entries);
+    blurred_qscale = av_malloc(sizeof(double) * rcc->num_entries);
+    if (!qscale || !blurred_qscale) {
+        av_free(qscale);
+        av_free(blurred_qscale);
+        return AVERROR(ENOMEM);
+    }
+    toobig = 0;
+
+    for (step = 256 * 256; step > 0.0000001; step *= 0.5) {
+        expected_bits = 0;
+        rate_factor  += step;
+
+        rcc->buffer_index = s->avctx->rc_buffer_size / 2;
+
+        /* find qscale */
+        for (i = 0; i < rcc->num_entries; i++) {
+            RateControlEntry *rce = &rcc->entry[i];
+
+            qscale[i] = get_qscale(s, &rcc->entry[i], rate_factor, i);
+            rcc->last_qscale_for[rce->pict_type] = qscale[i];
+        }
+        assert(filter_size % 2 == 1);
+
+        /* fixed I/B QP relative to P mode */
+        for (i = rcc->num_entries - 1; i >= 0; i--) {
+            RateControlEntry *rce = &rcc->entry[i];
+
+            qscale[i] = get_diff_limited_q(s, rce, qscale[i]);
+        }
+
+        /* smooth curve */
+        for (i = 0; i < rcc->num_entries; i++) {
+            RateControlEntry *rce = &rcc->entry[i];
+            const int pict_type   = rce->new_pict_type;
+            int j;
+            double q = 0.0, sum = 0.0;
+
+            for (j = 0; j < filter_size; j++) {
+                int index    = i + j - filter_size / 2;
+                double d     = index - i;
+                double coeff = a->qblur == 0 ? 1.0 : exp(-d * d / (a->qblur * a->qblur));
+
+                if (index < 0 || index >= rcc->num_entries)
+                    continue;
+                if (pict_type != rcc->entry[index].new_pict_type)
+                    continue;
+                q   += qscale[index] * coeff;
+                sum += coeff;
+            }
+            blurred_qscale[i] = q / sum;
+        }
 
-static inline double qp2bits(RateControlEntry *rce, double qp)
-{
-    if (qp <= 0.0) {
-        av_log(NULL, AV_LOG_ERROR, "qp<=0.0\n");
+        /* find expected bits */
+        for (i = 0; i < rcc->num_entries; i++) {
+            RateControlEntry *rce = &rcc->entry[i];
+            double bits;
+
+            rce->new_qscale = modify_qscale(s, rce, blurred_qscale[i], i);
+
+            bits  = qp2bits(rce, rce->new_qscale) + rce->mv_bits + rce->misc_bits;
+            bits += 8 * ff_vbv_update(s, bits);
+
+            rce->expected_bits = expected_bits;
+            expected_bits     += bits;
         }
-    return rce->qscale * (double)(rce->i_tex_bits + rce->p_tex_bits + 1) / qp;
-}
 
-static inline double bits2qp(RateControlEntry *rce, double bits)
-{
-    if (bits < 0.9) {
-        av_log(NULL, AV_LOG_ERROR, "bits<0.9\n");
+        ff_dlog(s->avctx,
+                "expected_bits: %f all_available_bits: %d rate_factor: %f\n",
+                expected_bits, (int)all_available_bits, rate_factor);
+        if (expected_bits > all_available_bits) {
+            rate_factor -= step;
+            ++toobig;
         }
-    return rce->qscale * (double)(rce->i_tex_bits + rce->p_tex_bits + 1) / bits;
+    }
+    av_free(qscale);
+    av_free(blurred_qscale);
+
+    /* check bitrate calculations and print info */
+    qscale_sum = 0.0;
+    for (i = 0; i < rcc->num_entries; i++) {
+        ff_dlog(s, "[lavc rc] entry[%d].new_qscale = %.3f  qp = %.3f\n",
+                i,
+                rcc->entry[i].new_qscale,
+                rcc->entry[i].new_qscale / FF_QP2LAMBDA);
+        qscale_sum += av_clip(rcc->entry[i].new_qscale / FF_QP2LAMBDA,
+                              s->avctx->qmin, s->avctx->qmax);
+    }
+    assert(toobig <= 40);
+    av_log(s->avctx, AV_LOG_DEBUG,
+           "[lavc rc] requested bitrate: %d bps  expected bitrate: %d bps\n",
+           s->bit_rate,
+           (int)(expected_bits / ((double)all_available_bits / s->bit_rate)));
+    av_log(s->avctx, AV_LOG_DEBUG,
+           "[lavc rc] estimated target average qp: %.3f\n",
+           (float)qscale_sum / rcc->num_entries);
+    if (toobig == 0) {
+        av_log(s->avctx, AV_LOG_INFO,
+               "[lavc rc] Using all of requested bitrate is not "
+               "necessary for this video with these parameters.\n");
+    } else if (toobig == 40) {
+        av_log(s->avctx, AV_LOG_ERROR,
+               "[lavc rc] Error: bitrate too low for this video "
+               "with these parameters.\n");
+        return -1;
+    } else if (fabs(expected_bits / all_available_bits - 1.0) > 0.01) {
+        av_log(s->avctx, AV_LOG_ERROR,
+               "[lavc rc] Error: 2pass curve failed to converge\n");
+        return -1;
+    }
+
+    return 0;
 }
 
 av_cold int ff_rate_control_init(MpegEncContext *s)
@@ -253,288 +635,54 @@ av_cold int ff_rate_control_init(MpegEncContext *s)
     return 0;
 }
 
-av_cold void ff_rate_control_uninit(MpegEncContext *s)
-{
-    RateControlContext *rcc = &s->rc_context;
-    emms_c();
-
-    av_expr_free(rcc->rc_eq_eval);
-    av_freep(&rcc->entry);
-}
-
-int ff_vbv_update(MpegEncContext *s, int frame_size)
-{
-    RateControlContext *rcc = &s->rc_context;
-    const double fps        = 1 / av_q2d(s->avctx->time_base);
-    const int buffer_size   = s->avctx->rc_buffer_size;
-    const double min_rate   = s->avctx->rc_min_rate / fps;
-    const double max_rate   = s->avctx->rc_max_rate / fps;
-
-    ff_dlog(s, "%d %f %d %f %f\n",
-            buffer_size, rcc->buffer_index, frame_size, min_rate, max_rate);
-
-    if (buffer_size) {
-        int left;
-
-        rcc->buffer_index -= frame_size;
-        if (rcc->buffer_index < 0) {
-            av_log(s->avctx, AV_LOG_ERROR, "rc buffer underflow\n");
-            rcc->buffer_index = 0;
-        }
-
-        left = buffer_size - rcc->buffer_index - 1;
-        rcc->buffer_index += av_clip(left, min_rate, max_rate);
-
-        if (rcc->buffer_index > buffer_size) {
-            int stuffing = ceil((rcc->buffer_index - buffer_size) / 8);
-
-            if (stuffing < 4 && s->codec_id == AV_CODEC_ID_MPEG4)
-                stuffing = 4;
-            rcc->buffer_index -= 8 * stuffing;
-
-            if (s->avctx->debug & FF_DEBUG_RC)
-                av_log(s->avctx, AV_LOG_DEBUG, "stuffing %d bytes\n", stuffing);
-
-            return stuffing;
-        }
-    }
-    return 0;
-}
-
-/**
- * Modify the bitrate curve from pass1 for one frame.
- */
-static double get_qscale(MpegEncContext *s, RateControlEntry *rce,
-                         double rate_factor, int frame_num)
-{
-    RateControlContext *rcc = &s->rc_context;
-    AVCodecContext *a       = s->avctx;
-    const int pict_type     = rce->new_pict_type;
-    const double mb_num     = s->mb_num;
-    double q, bits;
-    int i;
-
-    double const_values[] = {
-        M_PI,
-        M_E,
-        rce->i_tex_bits * rce->qscale,
-        rce->p_tex_bits * rce->qscale,
-        (rce->i_tex_bits + rce->p_tex_bits) * (double)rce->qscale,
-        rce->mv_bits / mb_num,
-        rce->pict_type == AV_PICTURE_TYPE_B ? (rce->f_code + rce->b_code) * 0.5 : rce->f_code,
-        rce->i_count / mb_num,
-        rce->mc_mb_var_sum / mb_num,
-        rce->mb_var_sum / mb_num,
-        rce->pict_type == AV_PICTURE_TYPE_I,
-        rce->pict_type == AV_PICTURE_TYPE_P,
-        rce->pict_type == AV_PICTURE_TYPE_B,
-        rcc->qscale_sum[pict_type] / (double)rcc->frame_count[pict_type],
-        a->qcompress,
-        rcc->i_cplx_sum[AV_PICTURE_TYPE_I] / (double)rcc->frame_count[AV_PICTURE_TYPE_I],
-        rcc->i_cplx_sum[AV_PICTURE_TYPE_P] / (double)rcc->frame_count[AV_PICTURE_TYPE_P],
-        rcc->p_cplx_sum[AV_PICTURE_TYPE_P] / (double)rcc->frame_count[AV_PICTURE_TYPE_P],
-        rcc->p_cplx_sum[AV_PICTURE_TYPE_B] / (double)rcc->frame_count[AV_PICTURE_TYPE_B],
-        (rcc->i_cplx_sum[pict_type] + rcc->p_cplx_sum[pict_type]) / (double)rcc->frame_count[pict_type],
-        0
-    };
-
-    bits = av_expr_eval(rcc->rc_eq_eval, const_values, rce);
-    if (isnan(bits)) {
-        av_log(s->avctx, AV_LOG_ERROR, "Error evaluating rc_eq \"%s\"\n", s->rc_eq);
-        return -1;
-    }
-
-    rcc->pass1_rc_eq_output_sum += bits;
-    bits *= rate_factor;
-    if (bits < 0.0)
-        bits = 0.0;
-    bits += 1.0; // avoid 1/0 issues
-
-    /* user override */
-    for (i = 0; i < s->avctx->rc_override_count; i++) {
-        RcOverride *rco = s->avctx->rc_override;
-        if (rco[i].start_frame > frame_num)
-            continue;
-        if (rco[i].end_frame < frame_num)
-            continue;
-
-        if (rco[i].qscale)
-            bits = qp2bits(rce, rco[i].qscale);  // FIXME move at end to really force it?
-        else
-            bits *= rco[i].quality_factor;
-    }
-
-    q = bits2qp(rce, bits);
-
-    /* I/B difference */
-    if (pict_type == AV_PICTURE_TYPE_I && s->avctx->i_quant_factor < 0.0)
-        q = -q * s->avctx->i_quant_factor + s->avctx->i_quant_offset;
-    else if (pict_type == AV_PICTURE_TYPE_B && s->avctx->b_quant_factor < 0.0)
-        q = -q * s->avctx->b_quant_factor + s->avctx->b_quant_offset;
-    if (q < 1)
-        q = 1;
-
-    return q;
-}
-
-static double get_diff_limited_q(MpegEncContext *s, RateControlEntry *rce, double q)
-{
-    RateControlContext *rcc   = &s->rc_context;
-    AVCodecContext *a         = s->avctx;
-    const int pict_type       = rce->new_pict_type;
-    const double last_p_q     = rcc->last_qscale_for[AV_PICTURE_TYPE_P];
-    const double last_non_b_q = rcc->last_qscale_for[rcc->last_non_b_pict_type];
-
-    if (pict_type == AV_PICTURE_TYPE_I &&
-        (a->i_quant_factor > 0.0 || rcc->last_non_b_pict_type == AV_PICTURE_TYPE_P))
-        q = last_p_q * FFABS(a->i_quant_factor) + a->i_quant_offset;
-    else if (pict_type == AV_PICTURE_TYPE_B &&
-             a->b_quant_factor > 0.0)
-        q = last_non_b_q * a->b_quant_factor + a->b_quant_offset;
-    if (q < 1)
-        q = 1;
-
-    /* last qscale / qdiff stuff */
-    if (rcc->last_non_b_pict_type == pict_type || pict_type != AV_PICTURE_TYPE_I) {
-        double last_q     = rcc->last_qscale_for[pict_type];
-        const int maxdiff = FF_QP2LAMBDA * a->max_qdiff;
-
-        if (q > last_q + maxdiff)
-            q = last_q + maxdiff;
-        else if (q < last_q - maxdiff)
-            q = last_q - maxdiff;
-    }
-
-    rcc->last_qscale_for[pict_type] = q; // Note we cannot do that after blurring
-
-    if (pict_type != AV_PICTURE_TYPE_B)
-        rcc->last_non_b_pict_type = pict_type;
-
-    return q;
-}
-
-/**
- * Get the qmin & qmax for pict_type.
- */
-static void get_qminmax(int *qmin_ret, int *qmax_ret, MpegEncContext *s, int pict_type)
-{
-    int qmin = s->lmin;
-    int qmax = s->lmax;
-
-    assert(qmin <= qmax);
-
-    switch (pict_type) {
-    case AV_PICTURE_TYPE_B:
-        qmin = (int)(qmin * FFABS(s->avctx->b_quant_factor) + s->avctx->b_quant_offset + 0.5);
-        qmax = (int)(qmax * FFABS(s->avctx->b_quant_factor) + s->avctx->b_quant_offset + 0.5);
-        break;
-    case AV_PICTURE_TYPE_I:
-        qmin = (int)(qmin * FFABS(s->avctx->i_quant_factor) + s->avctx->i_quant_offset + 0.5);
-        qmax = (int)(qmax * FFABS(s->avctx->i_quant_factor) + s->avctx->i_quant_offset + 0.5);
-        break;
-    }
-
-    qmin = av_clip(qmin, 1, FF_LAMBDA_MAX);
-    qmax = av_clip(qmax, 1, FF_LAMBDA_MAX);
-
-    if (qmax < qmin)
-        qmax = qmin;
+av_cold void ff_rate_control_uninit(MpegEncContext *s)
+{
+    RateControlContext *rcc = &s->rc_context;
+    emms_c();
 
-    *qmin_ret = qmin;
-    *qmax_ret = qmax;
+    av_expr_free(rcc->rc_eq_eval);
+    av_freep(&rcc->entry);
 }
 
-static double modify_qscale(MpegEncContext *s, RateControlEntry *rce,
-                            double q, int frame_num)
+int ff_vbv_update(MpegEncContext *s, int frame_size)
 {
     RateControlContext *rcc = &s->rc_context;
-    const double buffer_size = s->avctx->rc_buffer_size;
     const double fps        = 1 / av_q2d(s->avctx->time_base);
+    const int buffer_size   = s->avctx->rc_buffer_size;
     const double min_rate   = s->avctx->rc_min_rate / fps;
     const double max_rate   = s->avctx->rc_max_rate / fps;
-    const int pict_type      = rce->new_pict_type;
-    int qmin, qmax;
-
-    get_qminmax(&qmin, &qmax, s, pict_type);
 
-    /* modulation */
-    if (s->rc_qmod_freq &&
-        frame_num % s->rc_qmod_freq == 0 &&
-        pict_type == AV_PICTURE_TYPE_P)
-        q *= s->rc_qmod_amp;
+    ff_dlog(s, "%d %f %d %f %f\n",
+            buffer_size, rcc->buffer_index, frame_size, min_rate, max_rate);
 
-    /* buffer overflow/underflow protection */
     if (buffer_size) {
-        double expected_size = rcc->buffer_index;
-        double q_limit;
+        int left;
 
-        if (min_rate) {
-            double d = 2 * (buffer_size - expected_size) / buffer_size;
-            if (d > 1.0)
-                d = 1.0;
-            else if (d < 0.0001)
-                d = 0.0001;
-            q *= pow(d, 1.0 / s->rc_buffer_aggressivity);
+        rcc->buffer_index -= frame_size;
+        if (rcc->buffer_index < 0) {
+            av_log(s->avctx, AV_LOG_ERROR, "rc buffer underflow\n");
+            rcc->buffer_index = 0;
+        }
 
-            q_limit = bits2qp(rce,
-                              FFMAX((min_rate - buffer_size + rcc->buffer_index) *
-                                    s->avctx->rc_min_vbv_overflow_use, 1));
+        left = buffer_size - rcc->buffer_index - 1;
+        rcc->buffer_index += av_clip(left, min_rate, max_rate);
 
-            if (q > q_limit) {
-                if (s->avctx->debug & FF_DEBUG_RC)
-                    av_log(s->avctx, AV_LOG_DEBUG,
-                           "limiting QP %f -> %f\n", q, q_limit);
-                q = q_limit;
-            }
-        }
+        if (rcc->buffer_index > buffer_size) {
+            int stuffing = ceil((rcc->buffer_index - buffer_size) / 8);
 
-        if (max_rate) {
-            double d = 2 * expected_size / buffer_size;
-            if (d > 1.0)
-                d = 1.0;
-            else if (d < 0.0001)
-                d = 0.0001;
-            q /= pow(d, 1.0 / s->rc_buffer_aggressivity);
+            if (stuffing < 4 && s->codec_id == AV_CODEC_ID_MPEG4)
+                stuffing = 4;
+            rcc->buffer_index -= 8 * stuffing;
 
-            q_limit = bits2qp(rce,
-                              FFMAX(rcc->buffer_index *
-                                    s->avctx->rc_max_available_vbv_use,
-                                    1));
-            if (q < q_limit) {
             if (s->avctx->debug & FF_DEBUG_RC)
-                    av_log(s->avctx, AV_LOG_DEBUG,
-                           "limiting QP %f -> %f\n", q, q_limit);
-                q = q_limit;
-            }
-        }
-    }
-    ff_dlog(s, "q:%f max:%f min:%f size:%f index:%f agr:%f\n",
-            q, max_rate, min_rate, buffer_size, rcc->buffer_index,
-            s->rc_buffer_aggressivity);
-    if (s->rc_qsquish == 0.0 || qmin == qmax) {
-        if (q < qmin)
-            q = qmin;
-        else if (q > qmax)
-            q = qmax;
-    } else {
-        double min2 = log(qmin);
-        double max2 = log(qmax);
-
-        q  = log(q);
-        q  = (q - min2) / (max2 - min2) - 0.5;
-        q *= -4.0;
-        q  = 1.0 / (1.0 + exp(q));
-        q  = q * (max2 - min2) + min2;
+                av_log(s->avctx, AV_LOG_DEBUG, "stuffing %d bytes\n", stuffing);
 
-        q = exp(q);
+            return stuffing;
         }
-
-    return q;
+    }
+    return 0;
 }
 
-// ----------------------------------
-// 1 Pass Code
-
 static double predict_size(Predictor *p, double q, double var)
 {
     return p->coeff * var / (q * p->count);
@@ -836,161 +984,3 @@ float ff_rate_estimate_qscale(MpegEncContext *s, int dry_run)
     }
     return q;
 }
-
-// ----------------------------------------------
-// 2-Pass code
-
-static int init_pass2(MpegEncContext *s)
-{
-    RateControlContext *rcc = &s->rc_context;
-    AVCodecContext *a       = s->avctx;
-    int i, toobig;
-    double fps             = 1 / av_q2d(s->avctx->time_base);
-    double complexity[5]   = { 0 }; // approximate bits at quant=1
-    uint64_t const_bits[5] = { 0 }; // quantizer independent bits
-    uint64_t all_const_bits;
-    uint64_t all_available_bits = (uint64_t)(s->bit_rate *
-                                             (double)rcc->num_entries / fps);
-    double rate_factor          = 0;
-    double step;
-    const int filter_size = (int)(a->qblur * 4) | 1;
-    double expected_bits;
-    double *qscale, *blurred_qscale, qscale_sum;
-
-    /* find complexity & const_bits & decide the pict_types */
-    for (i = 0; i < rcc->num_entries; i++) {
-        RateControlEntry *rce = &rcc->entry[i];
-
-        rce->new_pict_type                = rce->pict_type;
-        rcc->i_cplx_sum[rce->pict_type]  += rce->i_tex_bits * rce->qscale;
-        rcc->p_cplx_sum[rce->pict_type]  += rce->p_tex_bits * rce->qscale;
-        rcc->mv_bits_sum[rce->pict_type] += rce->mv_bits;
-        rcc->frame_count[rce->pict_type]++;
-
-        complexity[rce->new_pict_type] += (rce->i_tex_bits + rce->p_tex_bits) *
-                                          (double)rce->qscale;
-        const_bits[rce->new_pict_type] += rce->mv_bits + rce->misc_bits;
-    }
-
-    all_const_bits = const_bits[AV_PICTURE_TYPE_I] +
-                     const_bits[AV_PICTURE_TYPE_P] +
-                     const_bits[AV_PICTURE_TYPE_B];
-
-    if (all_available_bits < all_const_bits) {
-        av_log(s->avctx, AV_LOG_ERROR, "requested bitrate is too low\n");
-        return -1;
-    }
-
-    qscale         = av_malloc(sizeof(double) * rcc->num_entries);
-    blurred_qscale = av_malloc(sizeof(double) * rcc->num_entries);
-    if (!qscale || !blurred_qscale) {
-        av_free(qscale);
-        av_free(blurred_qscale);
-        return AVERROR(ENOMEM);
-    }
-    toobig = 0;
-
-    for (step = 256 * 256; step > 0.0000001; step *= 0.5) {
-        expected_bits = 0;
-        rate_factor  += step;
-
-        rcc->buffer_index = s->avctx->rc_buffer_size / 2;
-
-        /* find qscale */
-        for (i = 0; i < rcc->num_entries; i++) {
-            RateControlEntry *rce = &rcc->entry[i];
-
-            qscale[i] = get_qscale(s, &rcc->entry[i], rate_factor, i);
-            rcc->last_qscale_for[rce->pict_type] = qscale[i];
-        }
-        assert(filter_size % 2 == 1);
-
-        /* fixed I/B QP relative to P mode */
-        for (i = rcc->num_entries - 1; i >= 0; i--) {
-            RateControlEntry *rce = &rcc->entry[i];
-
-            qscale[i] = get_diff_limited_q(s, rce, qscale[i]);
-        }
-
-        /* smooth curve */
-        for (i = 0; i < rcc->num_entries; i++) {
-            RateControlEntry *rce = &rcc->entry[i];
-            const int pict_type   = rce->new_pict_type;
-            int j;
-            double q = 0.0, sum = 0.0;
-
-            for (j = 0; j < filter_size; j++) {
-                int index    = i + j - filter_size / 2;
-                double d     = index - i;
-                double coeff = a->qblur == 0 ? 1.0 : exp(-d * d / (a->qblur * a->qblur));
-
-                if (index < 0 || index >= rcc->num_entries)
-                    continue;
-                if (pict_type != rcc->entry[index].new_pict_type)
-                    continue;
-                q   += qscale[index] * coeff;
-                sum += coeff;
-            }
-            blurred_qscale[i] = q / sum;
-        }
-
-        /* find expected bits */
-        for (i = 0; i < rcc->num_entries; i++) {
-            RateControlEntry *rce = &rcc->entry[i];
-            double bits;
-
-            rce->new_qscale = modify_qscale(s, rce, blurred_qscale[i], i);
-
-            bits  = qp2bits(rce, rce->new_qscale) + rce->mv_bits + rce->misc_bits;
-            bits += 8 * ff_vbv_update(s, bits);
-
-            rce->expected_bits = expected_bits;
-            expected_bits     += bits;
-        }
-
-        ff_dlog(s->avctx,
-                "expected_bits: %f all_available_bits: %d rate_factor: %f\n",
-                expected_bits, (int)all_available_bits, rate_factor);
-        if (expected_bits > all_available_bits) {
-            rate_factor -= step;
-            ++toobig;
-        }
-    }
-    av_free(qscale);
-    av_free(blurred_qscale);
-
-    /* check bitrate calculations and print info */
-    qscale_sum = 0.0;
-    for (i = 0; i < rcc->num_entries; i++) {
-        ff_dlog(s, "[lavc rc] entry[%d].new_qscale = %.3f  qp = %.3f\n",
-                i,
-                rcc->entry[i].new_qscale,
-                rcc->entry[i].new_qscale / FF_QP2LAMBDA);
-        qscale_sum += av_clip(rcc->entry[i].new_qscale / FF_QP2LAMBDA,
-                              s->avctx->qmin, s->avctx->qmax);
-    }
-    assert(toobig <= 40);
-    av_log(s->avctx, AV_LOG_DEBUG,
-           "[lavc rc] requested bitrate: %d bps  expected bitrate: %d bps\n",
-           s->bit_rate,
-           (int)(expected_bits / ((double)all_available_bits / s->bit_rate)));
-    av_log(s->avctx, AV_LOG_DEBUG,
-           "[lavc rc] estimated target average qp: %.3f\n",
-           (float)qscale_sum / rcc->num_entries);
-    if (toobig == 0) {
-        av_log(s->avctx, AV_LOG_INFO,
-               "[lavc rc] Using all of requested bitrate is not "
-               "necessary for this video with these parameters.\n");
-    } else if (toobig == 40) {
-        av_log(s->avctx, AV_LOG_ERROR,
-               "[lavc rc] Error: bitrate too low for this video "
-               "with these parameters.\n");
-        return -1;
-    } else if (fabs(expected_bits / all_available_bits - 1.0) > 0.01) {
-        av_log(s->avctx, AV_LOG_ERROR,
-               "[lavc rc] Error: 2pass curve failed to converge\n");
-        return -1;
-    }
-
-    return 0;
-}